JPH03128617A - Ground fault detector of reception/distribution facility - Google Patents

Abstract

PURPOSE:To prevent a ground fault current from shunting in ground fault, with not all the circuit breakers equipped with four poles, by installing switches, which are interlocked so as to perform the same switching action as tripolar receiving circuit breakers, between current transformers to sense the ground fault current and neutral phase ground points. CONSTITUTION:Switches 8a and 8b are connected between current transformers 6a and 6b and the ground points 9a and 9b of neutral phases 5a and 5b. When one phase of a three-phase bus bar 3a is grounded at a ground fault point 13 with a power source 1a supplying no power, a three-pole receiving circuit breaker 4a open, and a four-pole bus-bar circuit breaker 10 closed, a ground fault current flows to the ground point 9b and a ground fault detection relay 7b trips a three-pole receiving circuit breaker 4b. The circuit of the neutral phase 5a is opened with the switch 8a. Thereby a shunt flow of the ground fault current from the ground point 13 to the ground point 9a is not generated and ground fault can be detected correctly.

Description

【発明の詳細な説明】 〔発明の目的〕 （産業上の利用分野） 本発明は受配電設備の地絡検出装置に関する。[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a ground fault detection device for power receiving and distribution equipment.

（従来の技術） 従来、並列する複数の受変電系統に於ては、地絡電流が
地絡点より２つ以上の接地点に対して分流し、接地抵抗
がどの程度あり、その接地抵抗によりどのように分流す
るのかを把握するのが非常に困難で、地絡検出継電器の
検出レベルの設定が難しい。しかし、誤動作又は不動作
となるため、地絡保護が不十分となるので、避けなけれ
ばならず、このため地絡電流の分流を防止する方法とし
て、従来では受電しゃ断器及び母連しゃ断器を全て４極
としていたが、３極のしゃ断器に比べて非常に形状が大
きくなり、これらしゃ断器を収納した配電盤の盤幅／盤
奥行寸法を考えた場合、３極しゃ断器を収納した配電盤
と比較すると約３開度度も大きくなり、かつ非経済であ
った。(Prior art) Conventionally, in multiple parallel power receiving and substation systems, the ground fault current is divided from the ground fault point to two or more ground points, and the ground fault current is divided into two or more ground points. It is very difficult to understand how the current is divided, and it is difficult to set the detection level of the ground fault detection relay. However, it must be avoided because it will malfunction or not work, resulting in insufficient ground fault protection.For this reason, as a method to prevent the shunting of ground fault current, conventionally, power receiving circuit breakers and bus circuit breakers have been used. All of them had 4 poles, but they were much larger in size than 3-pole circuit breakers, and when considering the panel width/panel depth dimensions of the switchboards that housed these circuit breakers, it was difficult to compare them to the switchboards that housed 3-pole circuit breakers. In comparison, the opening degree was increased by about 3 degrees, and it was uneconomical.

（発明が解決しようとする課題） 本発明は上記の欠点を鑑みなされたもので、全てのしゃ
断器を４極とすることなく、地絡時の地絡電流の分流を
防止可能とせしめた地絡検出装置を供給することを目的
とする。(Problems to be Solved by the Invention) The present invention was made in view of the above-mentioned drawbacks, and it is possible to prevent the shunting of ground fault current at the time of a ground fault without making all circuit breakers 4 poles. The purpose is to provide fault detection equipment.

（課題を解決するための手段） 本発明は、地絡電流を感知する変流器と中性相接地点と
の間に、３極の受電しゃ断器の開閉動作と同一の動作を
するようインターロックをとった開閉器を具備した受配
電設備の地絡検出装置である。(Means for Solving the Problems) The present invention provides an interface between a current transformer that senses a ground fault current and a neutral grounding point so that the same operation as that of a three-pole power receiving circuit breaker operates. This is a ground fault detection device for power receiving and distribution equipment equipped with an unlocked switch.

（作　用） 本発明では、３極の受電しゃ断器が閉の場合は、電気的
インターロックにより上記受電しゃ断器と同−系統側に
ある開閉器を閉とし、３極受電しゃ断器が開の場合は、
開閉器を開とする。(Function) In the present invention, when a three-pole power receiving breaker is closed, an electrical interlock closes a switch on the same system side as the power receiving breaker, and the three-pole power receiving breaker is opened. In case,
Open the switch.

（実施例） 次に本発明の一実施例を説明する。第１図は２次側を星
形結線とする並列に接続された２台の変圧器２ａ、２ｂ
と、変圧器２ａ、２ｂの中性点を接地する接地線５ａ、
５ｂと、接地線５ａ、５ｂに接続された変流器６ａ、６
ｂと、変流器６ａ、　６ｂの２次側に接続されて地絡時
の電流を検出する地絡検出装置７ａ、７ｂと、変圧器２
ａ、２ｂの２次巻線に接続されて２次回路の三相母線３
ａ、３ｂを開閉する３極受電しゃ断器４ａ、４ｂと、接
地線５ａ、５ｂから分岐し前記２次回路と並列して配線
される中性線５ｃ、５ｄと、中性線５ｃ、５ｄ及び２次
回路の三相母線３ａ、３ｂと接続され変圧器２ａ、２ｂ
の並列運転を制御する４極母連しゃ断器１０とを具備し
てなる受配電設備の地絡検出装置を示している。即ち、
　ｌａ及び１ｂは電源、２ａは電源１ａに接続される変
圧器、２ｂは電源１ｂに接続される変圧器、３ａは変圧
器２ａの２次側の三相母線、５ａは変圧器２ａの２次側
の中性相、３ｂは変圧器２ｂの２次側の三相母線、５ｂ
は変圧器２ｂの２次側の中性相、　６ａは中性相５ａに
設けられた変流器、７ａは変流器６ａの２次側に具備さ
れた地絡検出継電器、９ａは中性相５ａの接地点、６ｂ
は中性相５ｂに設けられた変流器、７ｂは変流器６ｂの
２次側に具備された地絡検出継電器、９ｂは中性相５ｂ
の接地点である。(Example) Next, an example of the present invention will be described. Figure 1 shows two transformers 2a and 2b connected in parallel with a star connection on the secondary side.
and a grounding wire 5a that grounds the neutral points of the transformers 2a and 2b,
5b, and current transformers 6a, 6 connected to grounding wires 5a, 5b.
b, ground fault detection devices 7a and 7b connected to the secondary sides of current transformers 6a and 6b to detect current in the event of a ground fault, and transformer 2
The three-phase bus 3 of the secondary circuit is connected to the secondary windings a and 2b.
3-pole power reception circuit breakers 4a, 4b that open and close a, 3b, neutral wires 5c, 5d branched from grounding wires 5a, 5b and wired in parallel with the secondary circuit, and neutral wires 5c, 5d and The transformers 2a, 2b are connected to the three-phase buses 3a, 3b of the secondary circuit.
1 shows a ground fault detection device for power receiving and distribution equipment, which is equipped with a four-pole bus breaker 10 that controls parallel operation of the four-pole bus breaker 10. That is,
la and 1b are power supplies, 2a is a transformer connected to power supply 1a, 2b is a transformer connected to power supply 1b, 3a is a three-phase bus on the secondary side of transformer 2a, and 5a is a secondary side of transformer 2a. neutral phase on the side, 3b is the three-phase bus on the secondary side of transformer 2b, 5b
is a neutral phase on the secondary side of the transformer 2b, 6a is a current transformer provided in the neutral phase 5a, 7a is a ground fault detection relay provided on the secondary side of the current transformer 6a, and 9a is a neutral phase. Grounding point of phase 5a, 6b
is a current transformer provided in the neutral phase 5b, 7b is a ground fault detection relay provided on the secondary side of the current transformer 6b, and 9b is a neutral phase 5b.
This is the grounding point.

そして、４ａは変圧器２ａから三相母線３ａを通してつ
ながる３極受電しゃ断器、４ｂは変圧器２ｂから三相母
線３ｂを通してつながる３極受電しゃ断器である。又、
　８ａは変流器６ａと接地点９ａとの間に具備した開閉
器で３極受電しゃ断器４ａと電気的鎖錠がとっである。4a is a three-pole power reception breaker connected from the transformer 2a through the three-phase bus 3a, and 4b is a three-pole power reception breaker connected from the transformer 2b through the three-phase bus 3b. or,
Reference numeral 8a is a switch provided between the current transformer 6a and the ground point 9a, and is electrically locked with the three-pole power reception breaker 4a.

８ａは変流器６ｂと接地点９ｂとの間に具備した開閉器
で、３極受電しゃ断器４ｂと電気的鎖錠がとっである。8a is a switch provided between the current transformer 6b and the grounding point 9b, and is electrically locked with the three-pole power reception breaker 4b.

すなわち、３極受電しゃ断器４ａが閉の場合は開閉器８
ａも閉となり、３極受電しゃ断器４ａが開の場合は開閉
器８ａも開となる。同様に３極受電しゃ断器４ｂが閉の
場合は開閉器８ｂも閉となり５３極受電しゃ断器４ｂが
開の場合は開閉器８ｂも開となる。That is, when the 3-pole power receiving breaker 4a is closed, the switch 8
a is also closed, and when the three-pole power receiving circuit breaker 4a is open, the switch 8a is also opened. Similarly, when the 3-pole power reception breaker 4b is closed, the switch 8b is also closed, and when the 53-pole power reception breaker 4b is open, the switch 8b is also opened.

このようにすれば、電源１ａ及びｌｂが生きていて、３
極受電しゃ断器４ａ及び４ｂが閉で、４極母連しゃ断器
１０が開となっていて、３極負荷用しゃ断器１１ａが閉
の時に三相母線３ａの内の１つの相の地絡が地絡点１３
にて生じた場合は、地絡電流が接地点９ａに流れ込み、
地絡検出継電器７ａにより３極受電しゃ断器４ａを引き
外しさせるが、接地点９ｂへの分流は４極母連しゃ断器
１０が開のため生じない６次に、電源１ａに電源がなく
、３極受電しゃ断器４ａが開で４極母連しゃ断器１０が
閉となっている場合、すなわち電源１ｂにて全ての負荷
へ給電されている場合に三相母線３ａの内の１つの相が
地絡点１３にて地絡した時は、地絡電流は接地点９ｂに
は流れ込み地絡検出継電器７ｂにより３極受電しゃ断器
４ｂを引き外しする。この時、３極受電しゃ断器４ａは
開となっているので、開閉器８ａも開となっており、受
電しゃ断器が３極で中性相５ａを受電しゃ断器の所で切
ってなくても開閉器８ａにて中性相の回路を開いている
ため、地絡点１３から接地点９ａへの地絡電流の分流は
生じないことになり、適切な地絡検出が可能である。も
ちろん、上記の逆の場合で電源ｌｂに電源がなく、４極
母連しゃ断器１０が閉となっていて、電源１ａにて、全
ての負荷に給電している場合で、３極負荷用しゃ断器１
１ｂが閉の時、地絡が３極負荷用しゃ断器１１ｂと負荷
１２ｂとの間の三和母ｉ３ｂの内の１つの相において生
じた場合でも、地絡電流は接地点９ａには流れ込むが、
接地点９ｂには、開閉器８ｂが開のため分流しないこと
は言うまでもないことである。In this way, power supplies 1a and lb are alive and 3
When the pole power receiving breakers 4a and 4b are closed, the 4-pole bus breaker 10 is open, and the 3-pole load breaker 11a is closed, a ground fault occurs in one phase of the 3-phase bus 3a. Ground fault point 13
If a ground fault current occurs at the ground point 9a,
The ground fault detection relay 7a causes the 3-pole power receiving circuit breaker 4a to be tripped, but the shunt to the grounding point 9b does not occur because the 4-pole bus breaker 10 is open.6 Next, there is no power in the power supply 1a, When the pole power receiving breaker 4a is open and the 4-pole bus breaker 10 is closed, that is, when power is being supplied to all loads from the power supply 1b, one phase of the three-phase bus 3a is connected to ground. When a ground fault occurs at the contact point 13, the ground fault current flows into the ground point 9b and trips the three-pole power reception breaker 4b by the ground fault detection relay 7b. At this time, since the 3-pole power receiving breaker 4a is open, the switch 8a is also open, even if the power receiving breaker is 3 poles and the neutral phase 5a is not cut at the power receiving breaker. Since the neutral phase circuit is opened by the switch 8a, the ground fault current will not be shunted from the ground fault point 13 to the ground point 9a, allowing appropriate ground fault detection. Of course, in the opposite case to the above, when there is no power in the power supply lb, the 4-pole bus breaker 10 is closed, and the power supply 1a is supplying power to all loads, the 3-pole load breaker Vessel 1
1b is closed, even if a ground fault occurs in one phase of the three-pole load circuit breaker 11b and the load 12b, the ground fault current will flow into the grounding point 9a. ,
It goes without saying that no current is diverted to the ground point 9b because the switch 8b is open.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、３相４ｍ回路における地絡検出は、受
電しゃ断器を４極にしなくても３極でも十分可能となり
、その上、中性相に具備する開閉器は、低圧用のもので
良いので、簡易で取付も容易なため、それらを収納した
配電盤の像幅／盤奥行寸法を考えると、４極のしゃ断器
を各々の受電しゃ断器として収納した配電盤に比べて約
３開度度縮小することが出来るという効果がある。According to the present invention, ground fault detection in a 3-phase 4m circuit can be sufficiently performed with a 3-pole power receiving breaker instead of a 4-pole one, and in addition, the switch provided on the neutral phase is a low-voltage one. Since it is simple and easy to install, considering the image width/panel depth dimensions of the switchboard that houses them, the opening is about 3 degrees compared to a switchboard that houses four-pole circuit breakers as each power receiving circuit breaker. It has the effect of being able to reduce the size.

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

第１図は本発明の一実施例を示す地絡検出装置の構成図
である。 ２ａ・・・変圧器、２ｂ・・・変圧器、３ａ・・・三相
母線、３ｂ・・・三相母線、４ａ・・・３極受電しゃ断
器、４ｂ・・・３極受電しゃ断器、６ａ・・・変流器、
６ｂ・・・変流器、７ａ・・・地絡検出継電器、７ｂ・
・・地絡検出継電器、　８ａ・・・開閉器、８ｂ・・・
開閉器、１０・・・４極母連しゃ断器、１１ａ・・・３
極負荷用しゃ断器、 １１ｂ・・・３極負荷用しゃ断器、１２ａ・・・負荷。FIG. 1 is a configuration diagram of a ground fault detection device showing an embodiment of the present invention. 2a...Transformer, 2b...Transformer, 3a...Three-phase bus, 3b...Three-phase bus, 4a...3-pole power receiving breaker, 4b...3-pole power receiving breaker, 6a...Current transformer,
6b... Current transformer, 7a... Earth fault detection relay, 7b.
...Ground fault detection relay, 8a...Switch, 8b...
Switch, 10...4-pole bus breaker, 11a...3
Circuit breaker for pole load, 11b... Circuit breaker for three pole load, 12a... Load.

Claims (1)

【特許請求の範囲】[Claims] ２次側を星形結線とする並列に接続された複数の変圧器
と、これらの変圧器の中性点を接地する接地線と、この
接地線に接続された変流器と、この変流器の２次側に接
続されて地絡時の電流を検出する地絡検出装置と、前記
変圧器の２次巻線に接続されて２次回路を開閉する３極
受電しや断器と、前記接地線から分岐し前記２次回路と
並列して配線される中性線と、この中性線及び前記２次
回路と接続され前記複数の変圧器の並列運転を制御する
４極母連しや断器とを具備してなる受配電設備の地絡検
出装置。A plurality of transformers connected in parallel with star-shaped secondary connections, a grounding wire that grounds the neutral points of these transformers, a current transformer connected to this grounding wire, and this current transformation. a ground fault detection device connected to the secondary side of the transformer to detect current at the time of a ground fault; and a 3-pole power receiving and disconnecting device connected to the secondary winding of the transformer to open and close the secondary circuit; a neutral wire branched from the ground wire and wired in parallel with the secondary circuit; and a 4-pole mother chain connected to the neutral wire and the secondary circuit to control parallel operation of the plurality of transformers. A ground fault detection device for power receiving and distribution equipment, which is equipped with a disconnector and a disconnector.