JPH0540144A - Method for detecting fault point of transmission line - Google Patents
Method for detecting fault point of transmission lineInfo
- Publication number
- JPH0540144A JPH0540144A JP19550391A JP19550391A JPH0540144A JP H0540144 A JPH0540144 A JP H0540144A JP 19550391 A JP19550391 A JP 19550391A JP 19550391 A JP19550391 A JP 19550391A JP H0540144 A JPH0540144 A JP H0540144A
- Authority
- JP
- Japan
- Prior art keywords
- power transmission
- branch
- load
- distance
- capacity
- 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.)
- Granted
Links
Landscapes
- Locating Faults (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、送電系統の事故点標定
方法に係り、特に、送電端と受電端との間に分岐負荷が
接続された送電線の送電端から事故点までの距離を標定
するに好適な送電系統の事故点標定方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fault locating method for a power transmission system, and more particularly, to a distance from a power transmitting end of a power transmission line in which a branch load is connected between a power transmitting end and a power receiving end to the fault point. The present invention relates to a fault location method of a transmission system suitable for location.
【０００２】[0002]
【従来の技術】従来、送電線の送電端から事故点までの
距離を標定する場合、送電端の電気量、例えば電圧、電
流と送電線の送電端から分岐点までの距離及び送電線の
線路インピーダンスを標定基本要素とし、受電端（相手
端）負荷容量と分岐負荷容量を補正要素とし、標定基本
要素と補正要素とから送電線の送電端から事故点までの
距離を標定する方式が採用されている。2. Description of the Related Art Conventionally, when locating the distance from the power transmission end of a power transmission line to a fault point, the amount of electricity at the power transmission end, such as voltage and current, the distance from the power transmission end of the power transmission line to the branch point, and the transmission line A method is adopted in which the impedance is used as the locating basic element, the receiving end (counterpart) load capacity and the branch load capacity are as the correction elements, and the distance from the transmitting end of the transmission line to the fault point is determined from the locating basic element and the correction element. ing.
【０００３】[0003]
【発明が解決しようとする課題】しかし、従来の事故点
標定方法においては、補正要素としての分岐負荷容量を
分岐変電所の設備容量または平均負荷容量を整定値とし
て用いていたため、分岐負荷の容量が急激に変化したと
きには分岐負荷の容量が整定値と著しく異った値とな
り、整定値に基づいて標定距離を補正しても標定距離の
誤差が大きくなるという不具合がある。However, in the conventional fault location method, the branch load capacity as a correction element is used as the set value of the facility capacity or average load capacity of the branch substation. When a sudden change occurs, the capacity of the branch load becomes a value that is significantly different from the settling value, and there is a problem in that even if the orientation distance is corrected based on the setting value, the orientation distance error increases.
【０００４】本発明の目的は、送電線の送電端と事故点
までの標定距離を分岐負荷の容量変化に応じて順次修正
することができる送電系統の事故点標定方法を提供する
ことにある。An object of the present invention is to provide a fault point locating method for a power transmission system which can sequentially correct the locating distance between the power transmission end of the power transmission line and the fault point according to the change in the capacity of the branch load.
【０００５】[0005]
【課題を解決するための手段】前記目的を達成するため
に、本発明は、第１の標定方法として、送電端と受電端
との間に分岐負荷が接続された送電線の電気量のうち送
電端の電気量と前記送電線の送電端から分岐点までの距
離及び前記送電線の線路インピーダンスを標定基本要素
とし、受電端負荷容量と分岐負荷容量を補正要素とし、
標定基本要素と補正要素とから前記送電線の送電端から
事故点までの距離を標定し、かつ分岐負荷の電力消費量
の変化に従って補正要素の分岐負荷容量を順次修正し、
修正した分岐負荷容量に基づいて前記標定した距離を修
正する送電系統の事故点標定方法を採用したものであ
る。In order to achieve the above object, the present invention provides, as a first orientation method, a method of locating an electric quantity of a transmission line in which a branch load is connected between a power transmission end and a power reception end. The electricity amount at the power transmission end, the distance from the power transmission end of the power transmission line to the branch point, and the line impedance of the power transmission line are the orientation basic elements, and the power receiving end load capacity and the branch load capacity are the correction elements,
Locating the distance from the power transmission end of the transmission line to the fault point from the orientation basic element and the correction element, and correcting the branch load capacity of the correction element sequentially according to the change in the power consumption of the branch load,
This is a method for locating a fault point in a power transmission system that corrects the above-mentioned located distance based on the corrected branch load capacity.
【０００６】第１の標定方法を含む第２の標定方法とし
て、分岐負荷の電力消費量を検出し、この検出値から分
岐負荷の電力消費量を求めるようにした送電系統の事故
点標定方法を採用したものである。As a second orientation method including the first orientation method, there is a fault location method for a transmission system in which the power consumption of a branch load is detected and the power consumption of the branch load is obtained from the detected value. It was adopted.
【０００７】第１の標定方法を含む第３の標定方法とし
て送電端の送電容量と送電端から見た負荷の容量との差
を検出し、この検出値から分岐負荷の電力消費量を求め
るようにした送電系統の事故点標定方法を採用したもの
である。As a third orientation method including the first orientation method, the difference between the power transmission capacity of the power transmission end and the load capacity seen from the power transmission end is detected, and the power consumption of the branch load is calculated from the detected value. It adopts the fault location method of the power transmission system described above.
【０００８】[0008]
【作用】送電線の送電端から事故点までの距離を標定す
るに際し、分岐負荷の電力消費量の変化に従って補正要
素の分岐負荷容量を順次補正し、修正した分岐負荷容量
に基づいて標定した距離を修正するようにしたため、分
岐負荷の容量が事故発生時に大きく変動しても、分岐負
荷の容量変化に応じて標定した距離を順次修正すること
ができる。[Operation] When locating the distance from the transmission end of the transmission line to the fault point, the branch load capacity of the correction element is sequentially corrected according to the change in the power consumption of the branch load, and the distance determined based on the corrected branch load capacity Therefore, even if the capacity of the branch load fluctuates greatly when an accident occurs, it is possible to sequentially correct the determined distance according to the change in the capacity of the branch load.
【０００９】又、送電端の送電容量と送電端から見た負
荷の容量との差を検出し、この検出値から分岐負荷の電
力消費量を求めれば、分岐負荷の電力消費量を求めるこ
とができる。Further, if the difference between the power transmission capacity of the power transmission end and the capacity of the load seen from the power transmission end is detected and the power consumption of the branch load is calculated from the detected value, the power consumption of the branch load can be calculated. it can.
【００１０】[0010]
【実施例】以下、本発明の一実施例を図面に基づいて説
明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.
【００１１】図１において、変電所１０と変電所１２と
は６６ＫＶ用送電線１４を介して接続されており、変電
所１０の送電端１６から送電線１４を介して変電所１２
の受電端（相手端）１８に電力が供給されている。この
送電線１４の途中には分岐負荷として分岐変電所２０が
接続されている。In FIG. 1, the substation 10 and the substation 12 are connected via a 66 KV power transmission line 14, and the substation 12 is connected from the power transmission end 16 of the substation 10 via the power transmission line 14.
Power is supplied to the power receiving end (counterpart) 18 of the. A branch substation 20 is connected as a branch load in the middle of the power transmission line 14.
【００１２】変電所１０の集中制御所２２にはコントロ
ーラ２４が設置されており、このコントローラ２４には
送電端１６の電気量に関する情報及び変電所１２、分岐
変電所２０の電気量に関する情報が伝送ケーブルを介し
て供給されている。これら各種電気量のうち分岐変電所
２０の分岐負荷の容量は、平均電力消費量を示すＷＨ情
報がパルス信号でコントローラ２４へ入力されるように
なっている。即ち分岐変電所２０からは平均電力消費量
に応じたパルス信号がコントローラ２４のパルス分配器
２６に入力されている。パルス分配器２６の出力信号は
サイクリックデジタルテレメータ２８と８ビットのマイ
クロプロセッサ３０に入力されている。サイクリックデ
ジタルテレメータ２８は、複数の分岐変電所からのパル
ス信号がパルス分配器２６を介して入力された場合、各
パルス分配器２６からのパルス信号を順番に入力し、入
力したパルス信号を数値データに変換し、変換した数値
データの内容を表示するように構成されている。A controller 24 is installed in the centralized control station 22 of the substation 10, and information about the amount of electricity of the power transmission end 16 and information about the amounts of electricity of the substation 12 and the branch substation 20 are transmitted to the controller 24. Supplied via cable. Among the various electric quantities, the capacity of the branch load of the branch substation 20 is such that WH information indicating the average power consumption is input to the controller 24 as a pulse signal. That is, the pulse signal corresponding to the average power consumption is input from the branch substation 20 to the pulse distributor 26 of the controller 24. The output signal of the pulse distributor 26 is input to the cyclic digital telemeter 28 and the 8-bit microprocessor 30. When the pulse signals from a plurality of branch substations are input via the pulse distributor 26, the cyclic digital telemeter 28 inputs the pulse signals from each pulse distributor 26 in order and the input pulse signal is a numerical value. It is configured to convert the data and display the contents of the converted numerical data.
【００１３】マイクロプロセッサ３０はＷＨ／ＫＷ変換
部３２、演算部３４、ＢＣＤコード変換部３６から構成
されている。ＷＨ／ＫＷ変換部３２は平均電力消費量を
時間で微分して電力消費量の瞬時値を求めるように構成
されている。そしてＷＨ／ＫＷ変換部３２の出力信号は
ＢＣＤコード変換部３６によりＢＣＤコードに変換さ
れ、１６ビットのマイクロプロセッサ３８へ出力される
ようになっている。The microprocessor 30 comprises a WH / KW converter 32, a calculator 34, and a BCD code converter 36. The WH / KW converter 32 is configured to differentiate the average power consumption amount with respect to time to obtain an instantaneous value of the power consumption amount. The output signal of the WH / KW conversion unit 32 is converted into a BCD code by the BCD code conversion unit 36 and output to the 16-bit microprocessor 38.
【００１４】マイクロプロセッサ３８にはマイクロプロ
セッサ３０からの情報と共に送電端１６の電気量に関す
る情報、受電端１８と分岐変電所２０の電気量に関する
情報などが入力されるようになっている。そしてマイク
ロプロセッサ３８は各種入力情報に基づいて、次の
（１）式に示されるように、送電端１６から事故点まで
の距離Ｌを求めるように構成されている。In addition to the information from the microprocessor 30, information on the amount of electricity at the power transmission end 16 and information on the amounts of electricity at the power receiving end 18 and the branch substation 20 are input to the microprocessor 38. Then, the microprocessor 38 is configured to obtain the distance L from the power transmission end 16 to the accident point based on various input information, as shown in the following equation (1).
【００１５】なお、マイクロプロセッサ３０の部分は、
マイクロプロセッサ３８にて一括処理してもよい。The part of the microprocessor 30 is
The microprocessor 38 may perform batch processing.
【００１６】[0016]
【数１】 [Equation 1]
【００１７】マイクロプロセッサ３８には、送電端１６
の電気量（Ｖ，Ｉ，Ｉ1)、送電端１６から分岐点４０ま
での距離ｌ1及び送電線１４の線路インピーダンスＺが
入力されていると共に、補正要素として、受電端負荷容
量ＰＬ(２)、分岐負荷容量ＰＬ(１)が入力されている。
マイクロプロセッサ３８は各種入力情報を基に、前記
（１）式に従って送電線１４の送電端１６から事故点ま
での距離を標定するように構成されている。そして、こ
の距離Ｌを標定するに際して、前記入力情報を基に送電
端１６から事故点までの距離を概略標定し、マイクロプ
ロセッサ３０からの入力情報、即ち分岐変電所２０の電
力消費量の変化に従って補正要素の分岐負荷容量ＰＬ
(１)を順次修正する。この修正タイミングは１分間隔で
あり、各修正した分岐負荷容量に基づいて、標定した距
離を順次修正し、より正確な距離を標定するように構成
されている。The microprocessor 38 has a transmitting end 16
(V, I, I 1 ), the distance l 1 from the power transmission end 16 to the branch point 40, and the line impedance Z of the power transmission line 14 are input, and as a correction factor, the load capacitance PL (2 at the power receiving end). ), And the branch load capacity PL (1) is input.
The microprocessor 38 is configured to locate the distance from the power transmission end 16 of the power transmission line 14 to the accident point according to the above equation (1) based on various input information. Then, when locating this distance L, the distance from the power transmission end 16 to the accident point is roughly locating based on the input information, and according to the input information from the microprocessor 30, that is, the change in the power consumption of the branch substation 20. Compensation element branch load capacity PL
Modify (1) sequentially. The correction timing is one minute, and the corrected distance is sequentially corrected based on each corrected branch load capacity, and a more accurate distance is determined.
【００１８】このように、本実施例においては、距離Ｌ
の標定するに際して、分岐変電所２０の電力消費量の変
化に従って分岐負荷容量を一定時間毎に修正するように
しているため、分岐負荷容量が急激に変化しても、分岐
負荷容量の変化に応じて距離Ｌを正確に標定することが
できる。As described above, in this embodiment, the distance L
Since the branch load capacity is corrected every fixed time according to the change in the power consumption of the branch substation 20 when locating, the change in the branch load capacity depends on the change in the branch load capacity. Therefore, the distance L can be accurately located.
【００１９】次に、図２に示されるように、分岐変電所
２０Ａ、２０Ｂ、２０Ｃのうち分岐変電所２０ＣからＷ
Ｈ情報が得られない場合には、分岐変電所２０Ａ、２０
Ｂ、変電所１２からのＷＨ情報をパルス分配器２６を介
して入力し、送電端１６の送電容量Ｐ、送電端１６から
見た負荷容量、即ち分岐変電所２０Ａの負荷容量Ａ、分
岐変電所２０Ｂの負荷容量Ｂ、受電端１８の負荷容量Ｐ
Ｌ(２)を求め、送電容量Ｐと負荷容量との差から、次の
（２）式に示されように、分岐変電所２０Ｃの負荷容量
Ｃを求めることができる。Next, as shown in FIG. 2, of the branch substations 20A, 20B and 20C, the branch substation 20C to W are connected.
If H information cannot be obtained, branch substations 20A, 20
B, the WH information from the substation 12 is input via the pulse distributor 26, and the power transmission capacity P of the power transmission end 16 and the load capacity viewed from the power transmission end 16, that is, the load capacity A of the branch substation 20A, the branch substation 20B load capacity B, power receiving end 18 load capacity P
L (2) is calculated, and the load capacity C of the branch substation 20C can be calculated from the difference between the power transmission capacity P and the load capacity as shown in the following expression (2).
【００２０】 Ｃ＝Ｐ−{〔Ａ＋Ｂ＋ＰＬ(２）〕} …(２) この場合において、各変電所の遮断器の開閉情報を入力
すれば、休止端（その変電所を使用していないときの受
電端）を検出することができる。C = P-{[A + B + PL (2)]} (2) In this case, if the switching information of the circuit breaker of each substation is input, the rest end (when the substation is not used, The receiving end) can be detected.
【００２１】即ち、各変電所の遮断器の開閉情報と共に
各変電所からＷＨ情報を入力したときに、ＷＨ情報が得
られない場合としては、大別すると次の２通りの原因が
ある。That is, when the WH information is not obtained when the WH information is input from each substation together with the switching information of the circuit breaker of each substation, there are roughly the following two causes.
【００２２】（１）遮断器が切の状態で電流が流れない
場合。(1) When the circuit breaker is off and no current flows.
【００２３】（Ａ）事故によって遮断器を切状態にした
ときなる。(A) The circuit breaker is turned off due to an accident.
【００２４】（Ｂ）その変電所を利用していないとき。(B) When not using the substation.
【００２５】（２）遮断器が入の状態でも需要家が電気
を使用せず電流が流れていない場合。(2) The customer does not use electricity and no current flows even when the circuit breaker is on.
【００２６】上述した状態を考慮し、遮断器が「入」か
「切」かの情報を取り込むことにより、いずれかの原因
によってＷＨ情報が入力されないことを判別することが
できる。このため、この判別結果から休止端を検出する
ことができる。又休止端を検出したときには、休止端の
情報を演算式から除くことができ、無駄な演算処理を省
略することができる。In consideration of the above-mentioned state, it is possible to determine that the WH information is not input due to one of the causes by taking in the information of "ON" or "OFF" by the circuit breaker. Therefore, the pause end can be detected from this determination result. Further, when the pause edge is detected, the information of the pause edge can be removed from the arithmetic expression, and useless arithmetic processing can be omitted.
【００２７】[0027]
【発明の効果】以上説明したように、本発明によれば、
送電線の送電端と事故点までの標定距離を分岐負荷の容
量変化に応じて修正するようにしたため、分岐負荷の容
量変化に伴う標定誤差を抑制し、正確な距離を求めるこ
とができる。又、分岐負荷の電力消費量を直接検出しな
くても、送電端の送電容量と送電端から見た負荷の容量
との差から分岐負荷の電力消費量を求めることができる
ため、検出システムの簡素化に寄与することができる。As described above, according to the present invention,
Since the location distance between the transmission end of the power transmission line and the fault point is corrected according to the capacity change of the branch load, the location error due to the capacity change of the branch load can be suppressed, and an accurate distance can be obtained. Even if the power consumption of the branch load is not directly detected, the power consumption of the branch load can be calculated from the difference between the power transmission capacity of the power transmission end and the capacity of the load viewed from the power transmission end. It can contribute to simplification.
【図１】本発明が適用された実施例の構成図である。FIG. 1 is a configuration diagram of an embodiment to which the present invention is applied.
【図２】分岐負荷が複数のときの実施例を示す構成図で
ある。FIG. 2 is a configuration diagram showing an embodiment when there are a plurality of branch loads.
１０，１２ 変電所、 ２０，２０Ａ，２０Ｂ，２０Ｃ 分岐変電所、 １４ 送電線、 １６ 送電端、 １８ 送電端、 ２２ 集中制御所 ２４ コントローラ、 ２６ パルス分配器、 ２８ サイクリックデジタルテレメータ、 ３０，３８ マイクロプロセッサ、 ３２ ＷＨ／ＫＷ変換部、 ３４ 演算部、 ３６ ＢＣＤコード変換部、 ４０ 分岐点。 10, 12 substation, 20, 20A, 20B, 20C branch substation, 14 transmission line, 16 transmission end, 18 transmission end, 22 centralized control station 24 controller, 26 pulse distributor, 28 cyclic digital telemeter, 30, 38 Microprocessor, 32 WH / KW conversion section, 34 arithmetic section, 36 BCD code conversion section, 40 branch points.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 上所 操 宮城県仙台市青葉区一番町三丁目７番１号 東北電力株式会社内 (72)発明者 藤原 重男 宮城県仙台市青葉区一番町三丁目７番１号 東北電力株式会社内 (72)発明者 佐藤 今朝生 宮城県仙台市青葉区一番町三丁目７番１号 東北電力株式会社内 (72)発明者 石橋 孝二 宮城県多賀城市宮内二丁目２番１号 東北 電機製造株式会社内 (72)発明者 阿部 広隆 宮城県多賀城市宮内二丁目２番１号 東北 電機製造株式会社内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kamijo Koujo 3-7-1, Ichibancho, Aoba-ku, Sendai-shi, Miyagi Tohoku Electric Power Co., Inc. (72) Inventor Shigeo Fujiwara, Aoba-ku, Sendai-shi, Miyagi 3-7-1 Machi Tohoku Electric Power Co., Inc. (72) Inventor Imao Sato 3-7-1, Ichibancho, Aoba-ku, Sendai City, Miyagi Prefecture Tohoku Electric Power Co., Inc. (72) Koji Ishibashi Tagajo, Miyagi Prefecture 2-2-1 Miyauchi, Tohoku Electric Manufacturing Co., Ltd. (72) Inventor Hirotaka Abe 2-2-1 Miyauchi, Tagajo City, Miyagi Tohoku Electric Manufacturing Co., Ltd.
Claims (3)
された送電線の電気量のうち送電端の電気量と前記送電
線の送電端から分岐点までの距離及び前記送電線の線路
インピーダンスを標定基本要素とし、受電端負荷容量と
分岐負荷容量を補正要素とし、標定基本要素と補正要素
とから前記送電線の送電端から事故点までの距離を標定
し、かつ分岐負荷の電力消費量の変化に従って補正要素
の分岐負荷容量を順次修正し、修正した分岐負荷容量に
基づいて前記標定した距離を修正する送電系統の事故点
標定方法。1. A quantity of electricity of a power transmission end of a quantity of electricity of a power transmission line in which a branch load is connected between a power transmission end and a power reception end, a distance from the power transmission end of the power transmission line to a branch point, and a distance of the power transmission line. The line impedance is the orientation basic element, the receiving end load capacity and the branch load capacity are the correction elements, the distance from the transmitting end of the transmission line to the fault point is located from the orientation basic element and the correction element, and the power of the branch load is A method for locating a fault in a power transmission system, which sequentially corrects branch load capacities of correction elements according to changes in consumption, and corrects the located distance based on the corrected branch load capacities.
出値から分岐負荷の電力消費量を求める請求項１記載の
送電系統の事故点標定方法。2. The fault location method for a power transmission system according to claim 1, wherein the power consumption of the branch load is detected, and the power consumption of the branch load is obtained from the detected value.
の容量との差を検出し、この検出値から分岐負荷の電力
消費量を求める請求項１記載の送電系統の事故点標定方
法。3. The fault location method for a power transmission system according to claim 1, wherein a difference between the power transmission capacity of the power transmission end and the capacity of the load seen from the power transmission end is detected, and the power consumption of the branch load is calculated from the detected value. ..
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19550391A JP2678217B2 (en) | 1991-08-05 | 1991-08-05 | Fault location method for power transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19550391A JP2678217B2 (en) | 1991-08-05 | 1991-08-05 | Fault location method for power transmission system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0540144A true JPH0540144A (en) | 1993-02-19 |
| JP2678217B2 JP2678217B2 (en) | 1997-11-17 |
Family
ID=16342171
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19550391A Expired - Fee Related JP2678217B2 (en) | 1991-08-05 | 1991-08-05 | Fault location method for power transmission system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2678217B2 (en) |
-
1991
- 1991-08-05 JP JP19550391A patent/JP2678217B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2678217B2 (en) | 1997-11-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5124624A (en) | Arrangement for electrical measurement | |
| WO1999054744A1 (en) | Battery measuring terminal | |
| US7489122B2 (en) | Method and device for measuring voltage | |
| JPS61292067A (en) | Method for measuring electric energy | |
| JPH0540144A (en) | Method for detecting fault point of transmission line | |
| US5606249A (en) | Electrical apparatus with wide dynamic range for monitoring and protecting electric power systems | |
| US5150039A (en) | Electrical measuring transformer | |
| US6014021A (en) | Electricity meter using fuzzy logic circuit | |
| US6369584B1 (en) | Signal correction apparatus and signal correction method | |
| JPH08101244A (en) | Method for location of fault point in transmission line | |
| US6584365B1 (en) | Electronic trip device with offset correction means | |
| US3166135A (en) | Voltage measuring apparatus for use in weighbridges | |
| JPH04370769A (en) | Correction method of voltage and current signal by using a/d converter | |
| WO1999005533A3 (en) | System for measuring the alternating current equivalent series resistance of a conductor | |
| JPH0634022B2 (en) | Parallel multi-line ground fault fault location method | |
| JPS6216032Y2 (en) | ||
| JPH11215684A (en) | Protective relay device and its bit transmission method | |
| SU736246A1 (en) | Device for detecting faults of parallel line | |
| JP3013970B2 (en) | Current differential relay | |
| JPH063402A (en) | Fault locator | |
| JP2591119B2 (en) | Line fault location measurement method | |
| JPH06258378A (en) | Fault point standardizing apparatus using direction decided result | |
| SU1760533A1 (en) | Device for supply of loads with stabilized d c voltage | |
| JPH0585874B2 (en) | ||
| JPH04240572A (en) | Electronic type watthour meter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |