JPH03132436A - Different power supply mixed-contact detecting system and device therefor - Google Patents
Different power supply mixed-contact detecting system and device thereforInfo
- Publication number
- JPH03132436A JPH03132436A JP27255889A JP27255889A JPH03132436A JP H03132436 A JPH03132436 A JP H03132436A JP 27255889 A JP27255889 A JP 27255889A JP 27255889 A JP27255889 A JP 27255889A JP H03132436 A JPH03132436 A JP H03132436A
- Authority
- JP
- Japan
- Prior art keywords
- contact
- breaker
- power sources
- vehicle
- circuit breakers
- 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
- 238000001514 detection method Methods 0.000 claims abstract description 28
- 238000012864 cross contamination Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 claims description 2
- 230000002633 protecting effect Effects 0.000 abstract 1
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000004804 winding Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000009528 severe injury Effects 0.000 description 1
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- Emergency Protection Circuit Devices (AREA)
Abstract
Description
【発明の詳細な説明】
A、産業上の利用分野
本発明は、電気鉄道のき電区分、あるいは変電所間の電
源突き合わせ等の異種電源の混触を検出する技術に関す
る。DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a technology for detecting the mixing of different types of power sources, such as power source matching between power supply sections of electric railways or substations.
B0発明の概要
本発明は、異種電源の切替しゃ断器において異相混触事
故や異相混触事故が発生したときに一般の地絡事故、短
絡事故と区別がつかないが、これをしゃ断器に流れる電
流を検出して異種電源の混触事故を確実に検出し、一般
の事故と区分できるようにしたものである。B0 Summary of the Invention The present invention is designed to reduce the current flowing through the circuit breaker, which cannot be distinguished from general ground faults or short circuits when a different phase contact accident or different phase contact accident occurs in a switching breaker for different power sources. This system is designed to reliably detect cross-contact accidents between different types of power supplies and distinguish them from general accidents.
C1従来の技術
新幹線や津軽海峡線等の給電は、多数の異種電源が切替
しゃ断器を介して接続されている。この電気鉄道の負荷
は単相負荷であるため、一般にはスコツト変圧器又は変
形ウッドブリッジ変圧器によって、3相から単相の変換
を行っている。C1 Conventional technology In power supply systems such as the Shinkansen and the Tsugaru Kaikyo Line, a large number of different types of power sources are connected via switching circuit breakers. Since the electric railway load is a single-phase load, three-phase to single-phase conversion is generally performed using a Scott transformer or a modified Woodbridge transformer.
第2図は、変形ウッドブリッジ結線の例を示す結線図で
、1は3相2相変換用変圧器、2は昇圧用変圧器を示し
、3相2相変換用変圧器1は、1次巻線がY結線され、
電源に接続される。2次巻線はV相を並列接続した二重
三角結線となっている。Figure 2 is a wiring diagram showing an example of a modified Woodbridge connection, in which 1 shows a three-phase to two-phase conversion transformer, 2 shows a step-up transformer, and the three-phase to two-phase conversion transformer 1 is a primary The windings are Y-connected,
Connected to power. The secondary winding has a double triangular connection in which V-phases are connected in parallel.
この2次巻線の1組の出力端子a、c間の電圧をA座の
母線T、Fに、もう1組の出力端子b′d′に接続され
た昇圧用変圧器2の出力端子す。The voltage between one set of output terminals a and c of this secondary winding is transferred to the bus lines T and F of A, and the output terminal of the step-up transformer 2 connected to the other set of output terminals b'd'. .
6間の電圧はB座の母線T’、F′に接続される。The voltage between 6 and 6 is connected to the bus lines T' and F' of the B seat.
この出力端子a、cfJTの電圧をV、とすれば、もう
1組の出力端子b’、d’間の電圧はv2/(となり、
端子a、c間とb’、d′間の電圧の位相差は90度に
なっている。If the voltage of the output terminals a and cfJT is V, the voltage between the other set of output terminals b' and d' is v2/(,
The phase difference between the voltages between terminals a and c and between terminals b' and d' is 90 degrees.
昇圧変圧器2は、端子b’、d′間の電圧v、/(を昇
圧し、出力端子す、6間に電圧■、を発生させる。3は
切替セクションで、A座の母線′rに接続されたき電線
ATと、B座の母線Tに接続されたき電線BTの中間に
あり、画き電線とは絶縁手段4,5により絶縁されてい
る。また、ごの切替セクション3は、しゃ断器6を介し
てA座母線Tに、またしゃ断器7を介して13座母線1
゛′ に接続されている。8は列車等の車両を示してい
る。The step-up transformer 2 boosts the voltage v, /( between the terminals b' and d', and generates the voltage ■, between the output terminals S and 6. 3 is a switching section, and the voltage V, /( between the terminals b' and d' is increased. It is located between the connected feeder line AT and the feeder line BT connected to the bus line T of the B seat, and is insulated from the feeder line by insulation means 4 and 5. to the A seat bus line T via the circuit breaker 7, and to the 13 seat bus line 1 via the breaker 7.
Connected to ゛′. 8 indicates a vehicle such as a train.
なお、しゃ断器6.7は、真空しゃ断器が使用される。Note that a vacuum breaker is used as the circuit breaker 6.7.
切替しゃ断器の動作は、今車両8が図の右側から左側に
進行する場合は、車両8か絶縁手段4に達する手前でし
ゃ断器6を投入しくこのときしゃ断器7はしゃ断状態)
、切替セフシコン3をき電線ATと同じ電圧にして進入
させ、進入後絶縁手段5に達する前にしゃ断器6をしゃ
断し、同時にしゃ断器7を投入してB座母線BTと接続
し、異種電源間を無電弧で通過させる。The operation of the switching breaker is as follows: If the vehicle 8 is moving from the right side to the left side in the figure, the breaker 6 should be turned on before the vehicle 8 reaches the insulating means 4. At this time, the breaker 7 is in the cut off state.
, the switching safety controller 3 is set to the same voltage as the feeder line AT and then entered, and after entering, the breaker 6 is cut off before reaching the insulating means 5, and at the same time, the breaker 7 is turned on and connected to the B seat bus BT, and a different power source is connected. Pass through the space without arcing.
D1発明が解決しようとする課題
上記の切替しゃ断器6及び7は、常に片方だけ投入状態
にあり、列車の進行に合わせて切替わるようにしている
ので、動作回数は年間数万回に達し、切替しゃ断器の故
障検出や寿命管理が必要となる。D1 Problem to be Solved by the Invention The switching circuit breakers 6 and 7 described above are always in the closed state, and are switched in accordance with the progress of the train, so the number of operations reaches tens of thousands of times a year. Failure detection and life management of switching circuit breakers are required.
また、しゃ断器がアーク等により通電状態にあり、完全
にしゃ断しない中に別のしゃ断器が投入され、異種電源
の混触が起こると、異相混触事故や異相混触事故が発生
し、き電線や母線又は変圧器巻線に複雑な経路で電流が
流れ電源等のしゃ断器がしゃ断される。この事故電流は
一般の地絡事故や短絡事故と区別がつかず、そのため、
外線裸線の一過性地絡(短絡)と考え、強制再投入を繰
り返し、切替しゃ断器jこ深いダメージを与え、時とし
ては火災発生に発展することもあり、事故復旧に多大な
時間と要員を必要とする等の問題がある。In addition, if a breaker is in a energized state due to arcing, etc., and another breaker is turned on while the current is not completely cut off, causing contact between different types of power supplies, a different phase contact accident or a different phase contact accident will occur, and the feeder line or bus bar Alternatively, current flows through the transformer windings in a complicated path, causing a breaker such as a power supply to be disconnected. This fault current is indistinguishable from general ground faults and short circuit faults, and therefore,
Thinking that it was a temporary ground fault (short circuit) in the bare external wire, the operator repeatedly forced the circuit breaker to turn on again, causing severe damage to the switching breaker, which could even lead to a fire, and it would take a lot of time to recover from the accident. There are problems such as the need for personnel.
また、異相混触や異周波混触は、位相や周波数を比較し
て検出することは困難であり、混触事故の検出には適切
な手段がなかった。Further, it is difficult to detect different phase contact and different frequency contact by comparing phases and frequencies, and there has been no appropriate means for detecting mixed contact accidents.
そこで本発明は、これら異種電源の混触事故を一般の事
故と区別でき、しかも確実に検出できる方式を提供する
ことを目的とする。Therefore, an object of the present invention is to provide a method that can distinguish these accidents caused by contact between different types of power sources from general accidents, and can also reliably detect them.
E1課題を解決するための手段
上記の課題を解決するための手段は、異種電源の混触時
には、両切替しゃ断器に同一電流が流れることに着目し
、上記各しゃ断器に流れる電流を検出し、その両しゃ断
器に同時に電流が流れたときに異種電源の混触と判定す
る。E1 Means for solving the problem The means for solving the above problem focuses on the fact that the same current flows through both switching circuit breakers when different types of power sources come into contact, and detects the current flowing through each of the circuit breakers, When current flows through both circuit breakers at the same time, it is determined that there is a cross-contact between different types of power sources.
また、両切替しゃ断器に流れる電流を検出して両しゃ断
器に同時に流れたとき出力を出し、片方のみに流れてい
るときは出力を出さないようにした混触検出リレーを設
ける。Further, a contact detection relay is provided which detects the current flowing through both switching circuit breakers and outputs an output when the current flows through both circuit breakers at the same time, but does not output when the current flows through only one of the circuit breakers.
F0作用
正常運転時には、2台の切替しゃ断器は、常に片方だけ
投入状態にあり、異種電源の混触が起こったときは、第
1図の矢印で示す方向に電流が流れ、両しゃ断器に全く
同じ電流が流れるので、この両しゃ断器に同時に流れる
電流を検出して混触事故と判断し、いずれか一方のみ流
れているときは、正常と判断する。F0 action During normal operation, only one of the two switching circuit breakers is always in the on state, and when a cross-contact occurs between different types of power sources, current flows in the direction shown by the arrow in Figure 1, and both circuit breakers are completely disconnected. Since the same current flows, it is determined that there is a cross-contact accident by detecting the current flowing through both circuit breakers at the same time, and if only one is flowing, it is determined to be normal.
G、実施例
以下、本発明を第1図に示す一実施例に基づいて説明す
る。なお、第2図と同−又は同機能部分には、第2図と
同一符号を付して説明を省略する。G. Example Hereinafter, the present invention will be explained based on an example shown in FIG. Note that the same reference numerals as in FIG. 2 are given to the same or the same functional parts as in FIG. 2, and the explanation thereof will be omitted.
しかして、lOおよびIIは夫々しゃ断器6および7に
流れる電流を検出するための電流検出装置で、例えば変
流器等より成る。12は混触検出リレーで、該混触検出
リレー12は、1次および2次コイルから成る検出手段
121,122.123を備えている。この検出手段1
21と123とは、夫々電流検出装置10および11に
接続され、また検出手段122は1次コイルが2つから
成り、互いに逆極性にして電流検出装置10および11
に直接又は、検出手段121および123の1次コイル
と直列に接続されている。これら各検出手段の2次側に
は、2次誘起電圧で開閉する接点を有する。この接点は
、検出手段121と123は常開接点121aおよび1
23aを有し、また検出手段122は常閉接点122b
を有する。IO and II are current detection devices for detecting the currents flowing through the circuit breakers 6 and 7, respectively, and are comprised of, for example, current transformers. Reference numeral 12 denotes a contact detection relay, and the contact detection relay 12 is equipped with detection means 121, 122, and 123 consisting of primary and secondary coils. This detection means 1
21 and 123 are connected to the current detection devices 10 and 11, respectively, and the detection means 122 consists of two primary coils, and the polarity is reversed to connect the current detection devices 10 and 11.
or in series with the primary coils of the detection means 121 and 123. The secondary side of each of these detection means has a contact that opens and closes with a secondary induced voltage. The contacts 121 and 123 are normally open contacts 121a and 1
23a, and the detection means 122 has a normally closed contact 122b.
has.
そしてこれら各接点は、直列にして出力接点端子13.
14に接続される。Each of these contacts is connected in series to an output contact terminal 13.
14.
次に動作を説明すると、常時の列車負荷時には常にしゃ
断器6又は7のいずれか一方のみが投入状態となるので
、検出手段121又は123のいずれか一方と、検出手
段122の一方のコイルが付勢され、2次側のコイルに
電圧が発生し、検出手段+21又は123の常開接点1
21a又は123aの一方が閉じ、他方が開き、また検
出手段122は常時動作して常開接点122bを開く。Next, to explain the operation, since only one of the circuit breakers 6 or 7 is always closed when the train is under constant load, either one of the detection means 121 or 123 and one coil of the detection means 122 are connected. energized, a voltage is generated in the secondary coil, and the normally open contact 1 of the detection means +21 or 123
One of 21a or 123a is closed and the other is open, and the detection means 122 is always active and opens the normally open contact 122b.
従って出力接点端子13.14には、接点出力が出ない
。Therefore, no contact output is output to the output contact terminals 13 and 14.
次に例えば異相混触事故が発生すると、電流は矢印に示
すような方向で流れ、電流検出装置10と11の両方に
は全く同じ電流が流れる。このことにより検出手段12
1と123は同時に付勢され、その常開接点121a、
123aを閉じ、同時に検出手段122の1次側は相殺
し合って2次側には電圧が発生しないため、復帰し、そ
の常閉接点122bを閉じる。従って接点+21a、1
22b、123aはすべて閉じ、出力端子13触なども
、位相や周波数の比較によって検出する14には接点出
力が出され、これにより警報又は必要な保護動作を行わ
せる。無負荷の場合は12Ia、、I23aは開、12
2bは閉となり接点出力は出ない。Next, for example, when a different phase contact accident occurs, the current flows in the direction shown by the arrow, and the exact same current flows through both current detection devices 10 and 11. As a result, the detection means 12
1 and 123 are energized simultaneously, and their normally open contacts 121a,
123a is closed, and at the same time, the primary side of the detection means 122 cancels each other out and no voltage is generated on the secondary side, so it returns to its normal state and closes its normally closed contact 122b. Therefore, contact +21a, 1
22b and 123a are all closed, and a contact output is output to 14, which detects contact with the output terminal 13 by comparing phases and frequencies, thereby causing an alarm or necessary protective operation to be performed. In the case of no load, 12Ia, I23a is open, 12
2b is closed and no contact output is output.
なお、上記の実施例においては、変電所における異相混
触について説明したが、変電所間の電源突き合わせを行
うき電区分所にも適用でき、50Hz、601−(zの
混触、交流・直流等の異種電源の混触検出にも適用でき
る。In addition, in the above embodiment, the explanation was given regarding the mixture of different phases at a substation, but it can also be applied to a feeder distribution station where the power source is matched between substations, and it can be applied to the mixing of 50Hz, 601- It can also be applied to detection of contact between different types of power sources.
また、混触検出リレーは、コイルと接点出力からのもの
に限らず、半導体素子を用いた論理回路によっても構成
できることは勿論である。Further, the contact detection relay is not limited to a coil and a contact output, but can of course be constructed by a logic circuit using a semiconductor element.
H9発明の効果
以」二のように本発明は、異相混触又は異周波混のでは
なく、切替しゃ断器に流れる電流に着目してこれを検出
して混触の検出をするようにしたので、混触事故を確実
に検出でき、しかも一般の地絡、短絡事故と区別して検
出できるので、切替しゃ断器の劣化の兆候を早期に発見
てき、切替しゃ断器の寿命管理を適切に行うことができ
る等極めて優れた効果を奏する。H9 Effects of the Invention As stated in 2, the present invention focuses on and detects the current flowing through the switching breaker, rather than detecting cross-phase or different-frequency cross-contamination. Since accidents can be detected reliably and can be detected separately from general ground faults and short circuits, signs of deterioration of the switching breaker can be detected early and the service life of the switching breaker can be appropriately managed. It has excellent effects.
第1図は本発明の一実施例を示す結線図、第2図は従来
例の結線図を示す。
l・・・3相2相変換用変圧器、2・・押圧用変圧器、
3 切替セクション、4.5 絶縁手段、6.7・・・
切替しゃ断器、8・・・車両、10.II ・電流検
出装置。FIG. 1 is a wiring diagram showing one embodiment of the present invention, and FIG. 2 is a wiring diagram of a conventional example. l... 3-phase 2-phase conversion transformer, 2... pressure transformer,
3 switching section, 4.5 insulation means, 6.7...
Switching breaker, 8... Vehicle, 10. II - Current detection device.
Claims (2)
電源を接続するものにおいて、上記各しゃ断器に流れる
電流を検出し、その両しゃ断器に同時に流れる電流を検
出して異種電源の混触を検出するようにしたことを特徴
とする異種電源混触検出方式。(1) In devices where different types of power sources are connected to the switching section through separate circuit breakers, the current flowing through each of the above-mentioned circuit breakers is detected, and the current flowing simultaneously through both circuit breakers is detected to prevent cross-contact between different types of power sources. A method for detecting cross-contamination of different power sources.
電源を接続するものにおいて、前記各しゃ断器に流れる
電流を電気信号として検出する検出手段を設け、且つこ
れら両検出手段により検出された信号で出力を出し、い
ずれか一方のみの信号のときは出力を出さないようにし
た混触検出リレーを設けたことを特徴とする異種電源混
触検出装置。(2) In a device in which different types of power sources are connected to the switching sections through separate circuit breakers, a detection means is provided for detecting the current flowing through each of the circuit breakers as an electrical signal, and a signal detected by both of the detection means is provided. A cross-contact detection device for different power sources, characterized in that a cross-contact detection relay is provided that outputs an output when only one of the signals is received, and does not output an output when only one of the signals is received.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1272558A JP2743522B2 (en) | 1989-10-19 | 1989-10-19 | Different power supply contact detection method and device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1272558A JP2743522B2 (en) | 1989-10-19 | 1989-10-19 | Different power supply contact detection method and device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH03132436A true JPH03132436A (en) | 1991-06-05 |
JP2743522B2 JP2743522B2 (en) | 1998-04-22 |
Family
ID=17515582
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1272558A Expired - Lifetime JP2743522B2 (en) | 1989-10-19 | 1989-10-19 | Different power supply contact detection method and device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2743522B2 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010193683A (en) * | 2009-02-20 | 2010-09-02 | Tokuden Co Ltd | Three-phase/single-phase conversion voltage adjusting transformer |
WO2012023524A1 (en) * | 2010-08-20 | 2012-02-23 | 株式会社 東芝 | Magnetizing inrush current suppression device |
WO2012026423A1 (en) * | 2010-08-23 | 2012-03-01 | 株式会社 東芝 | Exciting inrush current suppression apparatus |
WO2013015356A1 (en) * | 2011-07-27 | 2013-01-31 | 株式会社 東芝 | Magnetizing inrush current suppression device |
CN109130958A (en) * | 2018-09-25 | 2019-01-04 | 交控科技股份有限公司 | Train crosses phase-separating section autocontrol method, device, mobile unit and electronic equipment |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6393640A (en) * | 1986-03-31 | 1988-04-23 | Railway Technical Res Inst | Relay method with different frequency mixed contact protecting for ac feeder circuit |
-
1989
- 1989-10-19 JP JP1272558A patent/JP2743522B2/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6393640A (en) * | 1986-03-31 | 1988-04-23 | Railway Technical Res Inst | Relay method with different frequency mixed contact protecting for ac feeder circuit |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010193683A (en) * | 2009-02-20 | 2010-09-02 | Tokuden Co Ltd | Three-phase/single-phase conversion voltage adjusting transformer |
WO2012023524A1 (en) * | 2010-08-20 | 2012-02-23 | 株式会社 東芝 | Magnetizing inrush current suppression device |
JP2012043712A (en) * | 2010-08-20 | 2012-03-01 | Toshiba Corp | Excitation inrush current suppressor |
AU2011291801B2 (en) * | 2010-08-20 | 2015-04-02 | Kabushiki Kaisha Toshiba | Magnetizing inrush current suppression apparatus |
WO2012026423A1 (en) * | 2010-08-23 | 2012-03-01 | 株式会社 東芝 | Exciting inrush current suppression apparatus |
JP2012043744A (en) * | 2010-08-23 | 2012-03-01 | Toshiba Corp | Excitation inrush current suppressor |
US9197057B2 (en) | 2010-08-23 | 2015-11-24 | Kabushiki Kaisha Toshiba | Magnetizing inrush current suppression apparatus |
WO2013015356A1 (en) * | 2011-07-27 | 2013-01-31 | 株式会社 東芝 | Magnetizing inrush current suppression device |
CN103608885A (en) * | 2011-07-27 | 2014-02-26 | 株式会社东芝 | Magnetizing inrush current suppression device |
US9583934B2 (en) | 2011-07-27 | 2017-02-28 | Kabushiki Kaisha Toshiba | Excitation inrush current suppression device |
CN109130958A (en) * | 2018-09-25 | 2019-01-04 | 交控科技股份有限公司 | Train crosses phase-separating section autocontrol method, device, mobile unit and electronic equipment |
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