JPH0246217Y2 - - Google Patents

Info

Publication number
JPH0246217Y2
JPH0246217Y2 JP254282U JP254282U JPH0246217Y2 JP H0246217 Y2 JPH0246217 Y2 JP H0246217Y2 JP 254282 U JP254282 U JP 254282U JP 254282 U JP254282 U JP 254282U JP H0246217 Y2 JPH0246217 Y2 JP H0246217Y2
Authority
JP
Japan
Prior art keywords
circuit
auxiliary
line
contacts
contact
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
JP254282U
Other languages
Japanese (ja)
Other versions
JPS58105739U (en
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed filed Critical
Priority to JP254282U priority Critical patent/JPS58105739U/en
Publication of JPS58105739U publication Critical patent/JPS58105739U/en
Application granted granted Critical
Publication of JPH0246217Y2 publication Critical patent/JPH0246217Y2/ja
Granted legal-status Critical Current

Links

Landscapes

  • Supply And Distribution Of Alternating Current (AREA)

Description

【考案の詳細な説明】 本考案は、環状母線の変電所における同期検出
のための計器用変圧器選択回路に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a potential transformer selection circuit for synchronization detection in a ring bus substation.

例えば、第１図に示すように４個所に遮断器
CB1〜CB4を設置した環状母線の各遮断器間に送
電線接続点を設け、これらの接続点にラインスイ
ツチLS1〜LS4を介して送電線l1〜l4を接続した変
電所においては、各遮断器CB1〜CB4の両側には
計器用変圧器を持たないことになり、同期検出に
要する電圧は送電線l1〜l4側に設置されたコンデ
ンサ形計器用変圧器PD1〜PD4の２次電圧を用い
ることになるが、その選択回路は遮断器CB1の分
について示せば第２図ａ，ｂのように構成してい
る。 For example, as shown in Figure 1, there are circuit breakers in four locations.
A substation in which transmission line connection points are provided between each circuit breaker of the ring bus bar with CB 1 to CB 4 installed, and transmission lines L 1 to L 4 are connected to these connection points via line switches LS 1 to LS 4 . In this case, there is no potential transformer on both sides of each circuit breaker CB 1 to CB 4 , and the voltage required for synchronization detection is determined by the capacitor type potential transformer installed on the transmission line L 1 to L 4 side. The secondary voltages PD 1 to PD 4 are used, and the selection circuit for the circuit breaker CB 1 is constructed as shown in FIGS. 2a and 2b.

第２図ａにおいて、COS1は遮断器CB1に対応
する選択スイツチ、１１Ａ〜１４Ａ及び１１Ｂ〜
１４ＢはPD選択用補助リレー、LS1a〜LS4aはラ
インスイツチLS1〜LS4の補助接点（常閉）、LS1b
〜LS4bはラインスイツチLS1〜LS4の補助接点
（常閉）CB1a〜CB4aは遮断器CB1〜CB4の補助接
点（常開）である。前記選択スイツチCOS1の右
側の接点下に構成されたシーケンス回路は遮断器
CB1の右側のPD選択回路であり、左側の接点下
に構成されたシーケンス回路は遮断器CB1の左側
のPD選択回路である。リレー１１Ａは選択時に
ラインスイツチLS1が投入されていれば付勢さ
れ、リレー１２ＡはラインスイツチLS2が投入さ
れているときに付勢され、リレー１３Ａはライン
スイツチLS1及びLS2が開、遮断器CB2及びCB3が
閉で、しかもラインスイツチLS3が投入されいる
ときに付勢され、リレー１４Ａは前記各リレー１
１Ａ〜１３Ａが消勢状態にあり、更に遮断器CB4
及びラインスイツチLS4が投入されているときに
付勢される。 In FIG. 2a, COS 1 is a selection switch corresponding to circuit breaker CB 1 , 11A to 14A and 11B to
14B is an auxiliary relay for PD selection, LS 1a to LS 4a are auxiliary contacts for line switches LS 1 to LS 4 (normally closed), LS 1b
-LS4b are auxiliary contacts (normally closed) of line switches LS1 to LS4 , and CB1a to CB4a are auxiliary contacts (normally open) of circuit breakers CB1 to CB4 . The sequence circuit configured under the right contact of the selection switch COS 1 is a circuit breaker.
It is the right PD selection circuit of CB 1 , and the sequence circuit configured under the left contact is the left PD selection circuit of circuit breaker CB 1 . Relay 11A is energized if line switch LS 1 is on at the time of selection, relay 12A is energized when line switch LS 2 is on, and relay 13A is energized when line switch LS 1 and LS 2 are open. When circuit breakers CB 2 and CB 3 are closed and line switch LS 3 is turned on, relay 14A is energized, and relay 14A is connected to each relay 1.
1A to 13A are de-energized, and circuit breaker CB 4
and is energized when line switch LS 4 is turned on.

また、遮断器CB1の左側のPD選択回路では、
リレー１４ＢはラインスイツチLS4が投入されて
いれば付勢され、リレー１３Ｂはラインスイツチ
LS4が開、遮断器CB4が閉で、しかもラインスイ
ツチLS3が投入されているときに付勢され、リレ
ー１２ＢはラインスイツチLS4及びLS3が開、遮
断器CB4及びCB3が閉で、しかもラインスイツチ
LS2が投入されているときに付勢され、リレー１
１Ｂは前記各リレー１２Ｂ〜１４Ｂが消勢状態に
あつて、遮断器CB2及びラインスイツチLS1が投
入されているときに付勢される。 Also, in the left PD selection circuit of circuit breaker CB 1 ,
Relay 14B is energized if line switch LS 4 is turned on, and relay 13B is energized when line switch LS 4 is turned on.
LS 4 is open, circuit breaker CB 4 is closed, and line switch LS 3 is closed, and relay 12B is energized when line switches LS 4 and LS 3 are open and circuit breaker CB 4 and CB 3 are closed. Closed and line switch
energized when LS 2 is closed, relay 1
1B is energized when each of the relays 12B to 14B is de-energized and the circuit breaker CB 2 and line switch LS 1 are closed.

上記のようなシーケンスによつてリレー１１Ａ
〜１４Ａ及び１１Ｂ〜１４Ｂが選択されると、そ
の接点１１Aa〜１４Aa及び１１Ba〜１４Baを
介して計器用変圧器PD1〜PD4の２次電圧が同期
検出回路SDへ供給される（第２図ｂ）。 By the above sequence, relay 11A
When ~14A and 11B~14B are selected, the secondary voltages of the potential transformers PD1 ~ PD4 are supplied to the synchronization detection circuit SD via their contacts 11Aa~14Aa and 11Ba~14Ba (Fig. 2). b).

このようにリレーシーケンスによつて開閉状態
に応じて計器用変圧器PD1〜PD4が選択され、そ
の２次電圧が同期検出のために用いられるが、図
示例は遮断器CB1 １台分についてであり、４台
の場合には４倍の数のシーケンス回路が必要であ
つて、回路構成が複雑になる。 In this way, the relay sequence selects potential transformers PD 1 to PD 4 depending on the open/close state, and the secondary voltage thereof is used for synchronization detection. In the case of four units, four times as many sequence circuits are required, and the circuit configuration becomes complicated.

なお、第３図に示すように遮断器CB1〜CB4の
両側（ライン側及び母線側）に計器用変圧器PD
を設置すれば、シーケンス回路は簡易化される
が、多数の計器用変圧器の設置によつて設備費が
高くなる。 In addition, as shown in Figure 3, potential transformers PD are installed on both sides (line side and bus side) of circuit breakers CB 1 to CB 4 .
Although the sequence circuit will be simplified if a number of potential transformers are installed, the installation cost will increase due to the installation of a large number of potential transformers.

本考案は上記事情に鑑みてなされたもので、計
器用変圧器の設置台数が少なくてすみ、しかも簡
易な回路構成の同期投入用計器用変圧器の選択回
路を提供することを目的とする。 The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a selection circuit for a synchronizing voltage transformer that requires less number of voltage transformers to be installed and has a simple circuit configuration.

以下、本考案を図示の実施例に基づいて詳細に
説明する。 Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

第４図ａ，ｂ，ｃは実施例の一実施例を示すも
ので、第１図に示すように４台の遮断器CB1〜
CB4を設置した場合である。図において、COS1
〜COS4は遮断器CB1〜CB4に対応する選択スイ
ツチであつて、常開、常閉の接点を２個ずつ持つ
てい。LS1a〜LS4aはラインスイツチLS1〜LS4の
補助接点（常開）、LS1b〜LS4bはラインスイツチ
LS1〜LS4の補助接点（常閉）、CB1a〜CB4aは遮
断器CB1〜CB4の補助接点（常開）、A1〜A4及び
B1〜B4はPD選択用補助リレーであつて、常開接
点A1a〜A4a及びB1a〜B4aを有する。 Figures 4a, b, and c show an example of the embodiment, and as shown in Figure 1, four circuit breakers CB 1 -
This is the case when CB 4 is installed. In the figure, COS 1
- COS 4 is a selection switch corresponding to circuit breakers CB 1 to CB 4 , and has two normally open and two normally closed contacts. LS 1a to LS 4a are auxiliary contacts (normally open) for line switches LS 1 to LS 4 , LS 1 b to LS 4 b are line switches
LS 1 to LS 4 auxiliary contacts (normally closed), CB 1 a to CB 4 a to circuit breakers CB 1 to CB 4 auxiliary contacts (normally open), A 1 to A 4 and
B1 to B4 are auxiliary relays for PD selection, and have normally open contacts A1a to A4a and B1a to B4a.

第４図ａは第１の回路で、４個のリレーA1〜
A4のコイルを対応するラインスイツチLS1〜LS4
の常開補助接点LS1a〜LS4a及び選択スイツチ
COS1〜COS4の常開接点を介して制御電源線Ｐ，
Ｎ間に接続するとともに、これら各直列回路のラ
インスイツチと選択スイツチの接続点t11〜t14間
を結ぶ環状連絡線を遮断器の補助接点等によつて
設けている。即ち、接続点t11，t12間にはライン
スイツチLS1の常閉補助接点LS1b、遮断器CB2の
補助接点CB2a及び選択スイツチCOS2の常閉接点
の直列回路を、接続点t12，t13間にはラインスイ
ツチLS2の常閉補助接点LS2b、遮断器CB3の補助
接点CB3a及び選択スイツチCOS3の常閉接点の直
列回路を、接続点t13，t14間にはラインスイツチ
LS3の常閉接点LS3b、遮断器CB4の常開補助接点
CB4a及び選択スイツチCOS4の常閉接点の直列回
路を、また接続点t14，t11間にはラインスイツチ
LS4の常閉接点LS4b、遮断器CB1の補助接点
CB1a及び選択スイツチCOS1の常閉接点の直列回
路をそれぞれ接続している。 Figure 4a shows the first circuit, which has four relays A 1 ~
Line switch corresponding to A 4 coil LS 1 ~ LS 4
Normally open auxiliary contacts LS 1a to LS 4a and selection switch
Control power line P, via the normally open contacts of COS 1 to COS 4 .
An annular connecting line is provided by an auxiliary contact of a circuit breaker or the like to connect between connection points t 11 to t 14 of the line switch and selection switch of each series circuit. That is, between the connection points t 11 and t 12 , a series circuit of the normally closed auxiliary contact LS 1b of the line switch LS 1 , the auxiliary contact CB 2a of the circuit breaker CB 2 , and the normally closed contact of the selection switch COS 2 is connected between the connection points t 11 and t 12. A series circuit of the normally closed auxiliary contact LS 2b of the line switch LS 2 , the auxiliary contact CB 3a of the circuit breaker CB 3 , and the normally closed contact of the selection switch COS 3 is connected between the connection points t 13 and t 12 and t 13 . There is a line switch
Normally closed contact LS 3 b of LS 3 , normally open auxiliary contact of circuit breaker CB 4
A series circuit of normally closed contacts of CB 4a and selection switch COS 4 is connected, and a line switch is connected between connection points t 14 and t 11 .
Normally closed contact LS 4 b of LS 4 , auxiliary contact of circuit breaker CB 1
The series circuits of normally closed contacts of CB 1 a and selection switch COS 1 are connected respectively.

第４図ｂは第２の回路で、その構成は第１の回
路と略同様であるが、リレーB1〜B4のコイルと
直列になる選択スイツチが対応するものでなく、
リレーB1にはスイツチCOS2というように一つず
つずらせている点及び環状連絡線の交点（接続点
t11〜t14に対応する点）t21〜t24の左右に位置する
ラインスイツチの常閉補助接点と選択スイツチの
常閉接点を置換させた点が第１の回路と異なる。 FIG. 4b shows a second circuit whose configuration is almost the same as the first circuit, but the selection switches connected in series with the coils of relays B 1 to B 4 do not correspond to each other;
Relay B 1 has switch COS 2 at the point shifted one by one and at the intersection of the circular connection lines (connection point).
Points corresponding to t11 to t14 ) This circuit differs from the first circuit in that the normally closed auxiliary contacts of the line switches located on the left and right of t21 to t24 are replaced with the normally closed contacts of the selection switch.

第４図ｃは第３の回路で、計器用変圧器PD1〜
PD4の２次電圧を第１の回路の対応するリレー
A1〜A4の接点A1a〜A4aを介して同期検出回路
SDの一方の入力端に、また第２の回路の対応す
るリレーB1〜B4の接点B1a〜B4aを介して他方の
入力端に供給するように構成している。 Figure 4c shows the third circuit, which connects potential transformers PD 1 to
The secondary voltage of PD 4 is connected to the corresponding relay of the first circuit.
Synchronous detection circuit through A1 ~ A4 contacts A1A ~ A4A
It is configured to be supplied to one input terminal of the SD and to the other input terminal via the contacts B 1 a to B 4 a of the corresponding relays B 1 to B 4 of the second circuit.

次に、動作について述べる。第１の回路では第
１図の単線結線図上の遮断器の右側の計器用変圧
器が選択され、第２の回路では遮断器の左側の計
器用変圧器が選択される。例えば、遮断器CB1を
投入する場合には、遮断器CB1に対応する選択ス
イツチCOS1を「入」操作すると、第１の回路に
おいてはラインスイツチLS1が投入状態であれば
補助リレーA1が付勢され、第２の回路において
はラインスイツチLS4が投入状態であれば補助リ
レーB4が付勢される。この結果、第３の回路の
接点A1a，B4aが閉成状態となり、同期検出回路
SDへは計器用変圧器PD1及びPD4の２次電圧が
供給される。 Next, the operation will be described. The first circuit selects the potential transformer to the right of the breaker on the single line diagram of FIG. 1, and the second circuit selects the potential transformer to the left of the breaker. For example, when closing circuit breaker CB 1 , if selection switch COS 1 corresponding to circuit breaker CB 1 is turned on, in the first circuit, if line switch LS 1 is closed, auxiliary relay A is turned on. 1 is energized, and in the second circuit, if line switch LS 4 is in the on state, auxiliary relay B 4 is energized. As a result, contacts A 1 a and B 4 a of the third circuit are closed, and the synchronization detection circuit
SD is supplied with the secondary voltages of potential transformers PD 1 and PD 4 .

また、第１の回路において、ラインスイツチ
LS1が開路状態にあり、遮断器CB2とラインスイ
ツチLS3が投入状態にある場合は、補助リレーA2
が選択され、同期検出回路SDには計器用変圧器
PD2の２次電圧が供給される。 Also, in the first circuit, the line switch
If LS 1 is open and circuit breaker CB 2 and line switch LS 3 are closed, auxiliary relay A2
is selected, and the synchronous detection circuit SD is a potential transformer.
The secondary voltage of PD 2 is supplied.

同様にして、ラインスイツチLS1，LS2が開路、
遮断器CB2，CB3とラインスイツチLS3が投入状
態にある場合は、補助リレーA3が選択され、同
期検出回路SDには計器用変圧器PD3の２次電圧
が供給される。 Similarly, line switches LS 1 and LS 2 are opened,
When the circuit breakers CB 2 and CB 3 and the line switch LS 3 are in the closed state, the auxiliary relay A 3 is selected and the secondary voltage of the potential transformer PD 3 is supplied to the synchronization detection circuit SD.

このような選択動作時には選択スイツチCOS1
の常閉接点が第１の回路では接続点t11の左側で、
また第２の回路では接続点t24の右側でそれぞれ
開路状態となり、環状連絡線に方向性が与えられ
る。この方向性は第１の回路と第２の回路では逆
になる。また、環状連絡線にラインスイツチLS1
〜LS4の常閉補助接点LS1b〜LS4bが存在するた
め、補助リレーは１個のみが選択されるようにな
り、計器用変圧器PD1〜PD4のパラレルランニン
グが防止される。 During such selection operation, the selection switch COS 1
In the first circuit, the normally closed contact of is to the left of the connection point t 11 ,
In addition, in the second circuit, the right side of the connection point t24 is respectively opened, giving directionality to the ring connecting line. This directionality is opposite between the first circuit and the second circuit. In addition, line switch LS 1 is installed on the circular connection line.
Since the normally closed auxiliary contacts LS 1b to LS 4 b of ~LS 4 are present, only one auxiliary relay is selected, and parallel running of the potential transformers PD 1 to PD 4 is prevented.

なお、環状連絡線に方向性を持たせるには、選
択スイツチの接点に代えてダイオードを配置して
もよい。ただし、制御電源が交流の場合、電流が
大の場合には、選択スイツチの接点を用いた方が
有効である。 Note that in order to give directionality to the annular connecting line, a diode may be placed in place of the contact of the selection switch. However, if the control power source is AC or the current is large, it is more effective to use the contacts of the selection switch.

以上のように本考案によれば、主回路を模擬し
た回路構成で母線側電圧を等価的に取出すことが
できるので、計器用変圧器は電源引込み側のみに
あればよく、設備費の軽減が図れる。しかも、回
路構成も非常に簡易である。 As described above, according to the present invention, the voltage on the busbar side can be taken out equivalently with a circuit configuration that simulates the main circuit, so the voltage transformer only needs to be installed on the power supply side, reducing equipment costs. I can figure it out. Moreover, the circuit configuration is also very simple.

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

第１図は環状母線を用いた変電所の系統構成の
一例を示す単線結線図、第２図ａ，ｂは従来の同
期投入用計器用変圧器の選択回路の接続図、第３
図は遮断器両側の電圧を取出す一手段を示す単線
結線図、第４図ａ，ｂ，ｃは本考案の一実施例を
示す接続図である。 CB1〜CB4……遮断器、CB1a〜CB4a……遮断
器の補助接点（常開）、LS1〜LS4……ラインスイ
ツチ、LS1a〜LS4a……ラインスイツチの補助接
点（常開）、LS1b〜LS4b……ラインスイツチの補
助接点（常閉）、l1〜l4……送電線、COS1〜COS4
……選択スイツチ、PD1〜PD4……計器用変圧
器、A1〜A4及びB1〜B4……補助リレー。 Figure 1 is a single line diagram showing an example of the system configuration of a substation using an annular busbar; Figures 2a and b are connection diagrams of a selection circuit for a conventional synchronization potential transformer;
The figure is a single-line connection diagram showing one means for taking out the voltage on both sides of the circuit breaker, and FIGS. 4a, 4b, and 4c are connection diagrams showing one embodiment of the present invention. CB 1 to CB 4 ...Breaker, CB 1 a to CB 4 a...Auxiliary contact of circuit breaker (normally open), LS 1 to LS 4 ...Line switch, LS 1 a to LS 4 a...Line switch Auxiliary contacts (normally open), LS 1b to LS 4b ... Line switch auxiliary contacts (normally closed), l 1 to l 4 ... power lines, COS 1 to COS 4
... Selection switch, PD 1 to PD 4 ... Potential transformer, A 1 to A 4 and B 1 to B 4 ... Auxiliary relay.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] ｎ個所に遮断器を設置した環状母線の各遮断器
間に送電線接続点を設け、各接続点にラインスイ
ツチを介して送電線を接続するとともに、送電線
側にのみ計器用変圧器を設置した系統において、
A1〜Anのｎ個の補助リレーのコイルを対応する
ラインスイツチの常開補助接点及び選択スイツチ
の常開接点を介して制御電源線間に接続するとと
もに、これら各直列回路のラインスイツチの常開
補助接点と選択スイツチの常開接点の接続点間を
結ぶ環状連絡線を設け、各接続点間に数の大きい
添字の補助リレーに対応する遮断器の常開補助接
点及び選択スイツチの常閉接点並びに数の小さい
添字の補助リレーに対応するラインスイツチの常
閉補助接点をそれぞれ挿設した第１の回路と、
B1〜Bnのｎ個の補助リレーのコイルを対応する
ラインスイツチの常開補助接点と一つ上位の番号
に対する選択スイツチの常開接点を介して制御電
源線間に接続するとともに、これら各直列回路の
ラインスイツチと選択スイツチの接続点間を結ぶ
環状連絡線を設け、各接続点間に数の大きい添字
の補助リレーに対応する遮断器の常開補助接点、
ラインスイツチの常閉補助接点及び選択スイツチ
の常閉補助接点をそれぞれ挿設した第２の回路
と、各計器用変圧器の２次電圧を前記第１の回路
の対応する補助リレーA1〜Anの接点を介して同
期検出回路の一方の入力端に、また前記第２の回
路の対応する補助リレーB1〜Bnの接点を介して
他方の入力端にそれぞれ供給する第３の回路とを
備えてなる同期投入用計器用変圧器の選択回路。 A power transmission line connection point is installed between each circuit breaker of a circular bus bar with circuit breakers installed at n locations, and a power transmission line is connected to each connection point via a line switch, and a voltage transformer is installed only on the power transmission line side. In the system that
The coils of n auxiliary relays A 1 to An are connected between the control power lines via the normally open auxiliary contacts of the corresponding line switches and the normally open contacts of the selection switch, and the An annular communication line is provided between the connection points of the open auxiliary contact and the normally open contact of the selection switch, and between each connection point, the normally open auxiliary contact of the circuit breaker corresponding to the auxiliary relay with a large number and the normally closed contact of the selection switch are connected. A first circuit in which a normally closed auxiliary contact of a line switch corresponding to a contact and a auxiliary relay with a small number of subscripts is inserted, respectively;
The coils of n auxiliary relays B 1 to Bn are connected between the control power lines via the normally open auxiliary contacts of the corresponding line switches and the normally open contacts of the selection switch for the next higher number, and each of these series An annular communication line is provided between the connection points of the line switch and selection switch of the circuit, and between each connection point there is a normally open auxiliary contact of the circuit breaker corresponding to the auxiliary relay with a large number of subscripts,
A second circuit in which the normally closed auxiliary contact of the line switch and the normally closed auxiliary contact of the selection switch are respectively inserted, and the secondary voltage of each instrument transformer are connected to the corresponding auxiliary relays A 1 to An of the first circuit. and a third circuit that supplies power to one input end of the synchronization detection circuit through the contacts of the synchronous detection circuit, and to the other input end of the second circuit through the contacts of the corresponding auxiliary relays B 1 to Bn. A selection circuit for a synchronous start-up voltage transformer.
JP254282U 1982-01-12 1982-01-12 Selection circuit for potential transformer for synchronization Granted JPS58105739U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP254282U JPS58105739U (en) 1982-01-12 1982-01-12 Selection circuit for potential transformer for synchronization

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP254282U JPS58105739U (en) 1982-01-12 1982-01-12 Selection circuit for potential transformer for synchronization

Publications (2)

Publication Number Publication Date
JPS58105739U JPS58105739U (en) 1983-07-19
JPH0246217Y2 true JPH0246217Y2 (en) 1990-12-06

Family

ID=30015524

Family Applications (1)

Application Number Title Priority Date Filing Date
JP254282U Granted JPS58105739U (en) 1982-01-12 1982-01-12 Selection circuit for potential transformer for synchronization

Country Status (1)

Country Link
JP (1) JPS58105739U (en)

Also Published As

Publication number Publication date
JPS58105739U (en) 1983-07-19

Similar Documents

Publication Publication Date Title
US7117105B2 (en) Method and apparatus for ground fault protection
JPH0246217Y2 (en)
DE3464293D1 (en) Load changer for switching step windings of a three-phase transformer
JPS6341801Y2 (en)
JPS6320097Y2 (en)
US1707269A (en) Electrical distribution system
RU1831746C (en) Electrical substation
SU838883A1 (en) Device for electric power supply of users
JPS6022773Y2 (en) Uninterruptible power supply device
JPS5841020U (en) power plant protection device
JP2705198B2 (en) Ground fault detector
JPS5932181Y2 (en) Double busbar uninterruptible switching device
ES8105525A1 (en) Circuit arrangement for multiple-pole fault current protection switches.
SU1436183A1 (en) Arrangement for automatic connection of stanby source for users
JPH057616Y2 (en)
JPH06311655A (en) Single operation detector
JP2577471B2 (en) Spot network power receiving system
JPH0116356Y2 (en)
SU826500A1 (en) Method and device for switching-on stand-by electric power source for users
SU423219A1 (en) METHOD OF SWITCHING RELAY PROTECTION KITS ON SECTIONAL LINES WITH NETWORK RESERVATION
JPS5921223A (en) Input device for ratio differential relay
JPH02111230A (en) Automatic synchronously closing system for many generators
JPS5926175B2 (en) Power plant external power supply receiving circuit
JPS5859328U (en) Network protector control device
JP2004166353A (en) Power distribution controller