JPH05146062A - Dc transmisstion facility - Google Patents
Dc transmisstion facilityInfo
- Publication number
- JPH05146062A JPH05146062A JP3301493A JP30149391A JPH05146062A JP H05146062 A JPH05146062 A JP H05146062A JP 3301493 A JP3301493 A JP 3301493A JP 30149391 A JP30149391 A JP 30149391A JP H05146062 A JPH05146062 A JP H05146062A
- Authority
- JP
- Japan
- Prior art keywords
- current
- ground fault
- return line
- forcibly
- metal return
- 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
Landscapes
- Direct Current Feeding And Distribution (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は直流送電システムに係
り、特に中性線を有する双極の直流送電設備に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power transmission system, and more particularly to a bipolar DC power transmission facility having a neutral wire.
【０００２】[0002]
【従来の技術】図５は直流送電設備の概略構成図を示
す。交流母線１，２は変換用変圧器３，３′及び４，
４′を介して、例えば多数個のサイリスタの直並列接続
からなる変換器５，５′及び６，６′に接続され、各サ
イリスタの点弧位相を制御することにより、交流を直流
に又は直流を交流に変換する。７，７′は直流送電線、
８は金属帰路線である。変換器５，６は直流電流のｉa
の大きさをサイリスタの点弧位相を変えることによって
制御する。この結果として交流母線１より変換用変圧器
３，変換器５、直流送電線７、変換用変圧器４を通し
て、交流母線２に流れる電力量を制御することができ
る。この電力の流れは変換器５を順変換器、変換器６を
逆変換器として運転した場合であるが、変換器６を順変
換器、変換器５を逆変換器として運転することにより、
電力の流れを交流母線２から交流母線１の方向にするこ
ともできる。2. Description of the Related Art FIG. 5 is a schematic block diagram of a DC power transmission facility. AC buses 1 and 2 are conversion transformers 3, 3'and 4,
4'is connected to converters 5, 5'and 6, 6'which are, for example, series-parallel connections of a large number of thyristors, and by controlling the ignition phase of each thyristor, AC is converted to DC or DC. Is converted into alternating current. 7, 7'is a DC transmission line,
8 is a metal return route. The converters 5 and 6 have a direct current i a
The magnitude of is controlled by changing the firing phase of the thyristor. As a result, the amount of electric power flowing from the AC bus 1 to the AC bus 2 can be controlled through the conversion transformer 3, the converter 5, the DC transmission line 7, and the conversion transformer 4. This flow of electric power is when the converter 5 is operated as a forward converter and the converter 6 is operated as an inverse converter. By operating the converter 6 as a forward converter and the converter 5 as an inverse converter,
The flow of electric power may be in the direction from the AC bus 2 to the AC bus 1.
【０００３】変換器５′，６′のグループも同様に、直
流電流ｉb を制御することにより、変換器５，６グルー
プと全く同じように、交流母線１と交流母線２の間で電
力のやり取りを行なうことができる。従って、このよう
な直流システムの構成は、金属帰路線８を共用している
ものの、２つの直流送電システムが独立して運転するこ
とができるように構成されていることになり、一般に双
極直流送電システムと呼ばれる。このような双極直流送
電システムでは一般に直流電流ｉa と直流電流ｉb とは
同一量となるよう制御することにより、金属帰路線８に
流れる電流を相互に打消し合い、小さな値とすることに
より金属帰路線８で発生する損失を小さくするよう変換
器を制御する。[0003] converter 5 ', 6' likewise group, by controlling the DC current i b, exactly like the converter 5 and 6 groups, power between AC buses 1 and the AC bus 2 Can interact. Therefore, the configuration of such a direct current system is configured such that the two direct current power transmission systems can operate independently although the metal return line 8 is commonly used. Called the system. In such a bipolar direct current power transmission system, in general, the direct current i a and the direct current i b are controlled to be the same amount, so that the currents flowing through the metal return line 8 cancel each other out to have a small value. The converter is controlled so as to reduce the loss generated on the metal return line 8.
【０００４】しかし、実際には直流電流ｉa と直流電流
ｉb とは変換器の制御誤差等もあり、完全に同一とする
ことは不可能であり、僅かの差電流が金属帰路線８に流
れることになる。更に過渡的に直流電流ｉa と直流電流
ｉb とに差を持たせて運転させたり、双極の内の片極を
停止させることにより、金属帰路線８には大きな直流電
流が流れる。この直流電流が大地を通して流れないよう
図５に示されるように接地点は９の一点のみとしてい
る。従って、変換器５，５′側の中性点10では金属帰路
線８の抵抗値と金属帰路線８に流れる直流電流の積に相
当する直流電圧が発生することになる。However, in reality, the direct current i a and the direct current i b cannot be made completely the same due to a control error of the converter and the like, and a slight difference current flows to the metal return line 8. It will flow. Further, a large direct current flows through the metal return line 8 by transiently operating with a difference between the direct current i a and the direct current i b , or by stopping one of the bipolar electrodes. In order to prevent this direct current from flowing through the ground, there is only one ground point 9, as shown in FIG. Therefore, a DC voltage corresponding to the product of the resistance value of the metal return line 8 and the DC current flowing through the metal return line 8 is generated at the neutral point 10 on the converter 5, 5'side.
【０００５】このような状態で金属帰路線８で地絡事故
が発生すると図６のように地絡点11から接地点９を通
し、地絡電流ｉf が流れる。この地絡電流を切るため
に、従来は直流しゃ断器12を中性点10に設置し、地絡事
故を検出するとこの直流しゃ断器を投入し、強制的に中
性点10の電圧を零とすることによって、地絡点の地絡電
流ｉf を零とする。この状態では直流電流ｉa とｉb の
差電流は、金属帰路線８と接地点９から直流しゃ断器12
を通した中性点10までの回路とに分流することになり、
その後直流しゃ断器12を開くことにより直流電流ｉa と
ｉb の差電流は全て金属帰路線８に流れることになり、
直流送電システムの電流配分は事故前の状態に復帰す
る。When a ground fault occurs on the metal return route 8 in such a state, a ground fault current i f flows from the ground fault point 11 through the ground point 9 as shown in FIG. In order to cut off this ground fault current, conventionally, a DC breaker 12 was installed at the neutral point 10, and when a ground fault was detected, this DC breaker was turned on and the voltage at the neutral point 10 was forced to zero. By doing so, the ground fault current if at the ground fault point becomes zero. In this state, the difference between the DC currents i a and i b is the DC breaker 12 from the metal return line 8 and the ground point 9.
It will be shunted to the circuit up to neutral point 10 through
After that, by opening the DC breaker 12, all the current difference between the DC currents i a and i b will flow to the metal return line 8,
The current distribution of the DC transmission system returns to the state before the accident.
【０００６】[0006]
【発明が解決しようとする課題】一般にしゃ断器は電流
が零となる点で、しゃ断器内のアークを消弧する構成と
なっているため、電流に零点が発生しない直流電流のよ
うな場合には、この電流をしゃ断するための特別な構
成，技術が必要であり、従って直流しゃ断器12は高価な
ものとなる。Generally, a circuit breaker is designed to extinguish the arc in the circuit breaker at the point where the current becomes zero. Requires a special configuration and technique to cut off this current, and therefore the DC breaker 12 becomes expensive.
【０００７】本発明は上記事情に鑑みてなされたもので
あり、高価な直流しゃ断器を使用せず、金属帰路線で発
生した地絡事故を除去することを可能とする直流送電設
備を提供することを目的としている。The present invention has been made in view of the above circumstances, and provides a DC power transmission facility capable of eliminating a ground fault occurring on a metal return route without using an expensive DC breaker. The purpose is to.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するた
め、本発明は金属帰路線を備えた双極直流送電システム
において、金属帰路線に地絡事故が発生したとき、一方
の極の直流電流を一旦強制的に増加させてから減少させ
ることにより、各極夫々の直流電流が同一となる点を強
制的につくり出す制御機能を具備した。In order to achieve the above object, the present invention provides a bipolar DC power transmission system provided with a metal return line, in which a DC current of one pole is changed when a ground fault occurs on the metal return line. It was equipped with a control function that forcibly creates a point where the DC currents of each pole become the same by forcibly increasing and then decreasing.
【０００９】[0009]
【作用】金属帰路線における地絡事故は本来金属帰路線
に直流電流ｉa とｉb の差電流が流れるために発生し、
地絡電流もこの差電流の一部が分流しているために継続
して流れるのが主原因であるため、この金属帰路線に流
れる差電流を零にするようにする。そのため変換器のサ
イリスタに対する点弧位相角の制御によって直流電流に
よる差電流を零にする。[Operation] The ground fault on the metal return route originally occurs because the differential current between the direct currents i a and i b flows on the metal return route.
Since the ground fault current is mainly caused to continue flowing because a part of this difference current is shunted, the difference current flowing to this metal return route should be set to zero. Therefore, the difference current due to the direct current is made zero by controlling the firing phase angle of the converter with respect to the thyristor.
【００１０】[0010]
【実施例】以下図面を参照して実施例を説明する。Embodiments will be described below with reference to the drawings.
【００１１】図１は本発明による直流送電設備の一実施
例の構成図であり、ハード構成そのものは図５と同様で
ある。したがって金属帰路線に地絡事故が発生した状態
として示し、その他の構成についての説明は省略する。FIG. 1 is a configuration diagram of an embodiment of a DC power transmission facility according to the present invention, and the hardware configuration itself is the same as that of FIG. Therefore, it is indicated that a ground fault has occurred on the metal return route, and the description of other configurations will be omitted.
【００１２】図２は金属帰路線に流れる電流と時間との
関係を示す図であり、横軸に時間を、縦軸に電流値をと
ったものである。図２では時刻ｔ0 〜ｔ1 が地絡発生前
の定常状態時を表わし、この例では電流ｉa とｉb とは
差電流13の大きさがある。そして時刻ｔ1 にて地絡事故
が発生すると、一方の電流ｉa を強制的に一旦上昇させ
た後、減少させ、時刻ｔ2 にて他方の電流ｉb と電流値
を同じにして地絡電流を消滅させ、更に時刻ｔ3 まで減
少させた後、定常値に戻すようにしたものである。以上
により金属帰路線に流れる直流差電流を零にすることが
でき、高価な直流しゃ断器を用いずに、安価な直流送電
設備を供給することができる。FIG. 2 is a diagram showing the relationship between the current flowing through the metal return route and time, in which the horizontal axis represents time and the vertical axis represents current value. In FIG. 2, times t 0 to t 1 represent a steady state before the occurrence of a ground fault, and in this example, there is a difference current 13 between the currents i a and i b . When a ground fault occurs at time t 1 , one of the currents i a is forcibly increased once and then decreased, and at time t 2 , the current value of the other current i b becomes the same as that of the ground fault, and the ground fault occurs. The current is extinguished, further reduced until time t 3, and then returned to a steady value. As described above, the DC differential current flowing through the metal return route can be made zero, and inexpensive DC power transmission equipment can be supplied without using an expensive DC breaker.
【００１３】図３は他の実施例を説明するための、金属
帰路線に流れる電流特性を示す。図３では時刻ｔ1 にお
いて、金属帰路線に地絡事故が発生し、これを検出する
と同時に直流電流ｉa を強制的に大きくし、その後徐々
に減少させていく。時刻ｔ2で直流電流ｉa とｉbが同一
となり、地絡事故が消滅した時点でこれを検出し、その
後事故発生前の定常運転状態に復帰させる。このように
することにより、直流電流ｉa の変動、即ち、電力量の
変化を最小限に抑制することができる。FIG. 3 shows the characteristics of the current flowing in the metal return line for explaining another embodiment. In FIG. 3, at time t 1 , a ground fault occurs on the metal return route, and when this is detected, the direct current i a is forcibly increased and then gradually decreased. At time t 2 , the DC currents i a and i b become the same, and this is detected when the ground fault disappears, and then the normal operation state before the accident occurs is restored. By doing so, the fluctuation of the direct current i a , that is, the change of the electric energy can be suppressed to the minimum.
【００１４】図４は更に他の実施例を説明するための、
金属帰路線に流れる電流特性を示す。時刻ｔ1 で金属帰
路線に地絡事故が発生したとき、この事故を検出すると
同時に、本実施例では変換器５，６の制御により、直流
電流ｉa を強制的に大きくし、その後強制的に減少させ
ていく。このようにすることにより、時刻ｔ2 において
強制的に直流電流ｉa とｉb が同一となる点をつくるこ
とができる。本実施例ではこの制御は予め設定した時刻
ｔ3 まで行ない、その後事故発生前の定常運転状態に復
帰する。FIG. 4 is a view for explaining still another embodiment,
The characteristics of the current flowing on the metal return route are shown. At the time t 1 , when a ground fault occurs on the metal return route, this fault is detected, and at the same time, in the present embodiment, the DC current i a is forcibly increased by the control of the converters 5 and 6 and then forced. To decrease. By doing so, it is possible to forcibly make a point where the direct currents i a and i b become the same at time t 2 . In the present embodiment, this control is performed until a preset time t 3 , and then the normal operation state before the accident occurs is restored.
【００１５】上記実施例によれば金属帰路線で発生した
地絡事故電流を直流しゃ断器を用いずに消滅することが
できる。要するに、変換器に本来具備している直流電流
制御機能を応用することにより、容易に直流電流ｉa を
強制的に大きくし、その後徐々に時刻ｔ2 まで減少さ
せ、また時刻ｔ3まで増加させ、更に時刻ｔ4 まで減少
させる。このような制御を行なうことにより、直流電流
ｉa とｉb が同一となる回数を増加させ、確実に地絡事
故電流を消滅させることができる。According to the above embodiment, the ground fault accident current generated on the metal return route can be extinguished without using a DC breaker. In short, by applying the DC current control function originally possessed by the converter, the DC current i a can easily be forcibly increased and then gradually decreased until time t 2 and then increased until time t 3. , Further decrease until time t 4 . By performing such control, it is possible to increase the number of times that the DC currents i a and i b are the same and to surely eliminate the ground fault accident current.
【００１６】[0016]
【発明の効果】以上説明したように、本発明によれば変
換器の直流電流制御機能を応用することにより、金属帰
路線の地絡事故電流を高価な直流しゃ断器を用いず、安
価な方法で消滅させることができる。As described above, according to the present invention, by applying the DC current control function of the converter, the earth fault current on the metal return route can be inexpensively manufactured without using an expensive DC circuit breaker. Can be eliminated with.
【図１】双極直流送電システムの構成において地絡事故
が発生している状態を示す図。FIG. 1 is a diagram showing a state in which a ground fault has occurred in the configuration of a bipolar DC power transmission system.
【図２】金属帰路線に流れる電流を零にするための特性
図。FIG. 2 is a characteristic diagram for making the current flowing through the metal return route to zero.
【図３】金属帰路線に流れる電流を零にするための他の
特性図。FIG. 3 is another characteristic diagram for reducing the current flowing through the metal return route to zero.
【図４】金属帰路線に流れる電流を零にするための更に
他の特性図。FIG. 4 is another characteristic diagram for making the current flowing through the metal return line to zero.
【図５】双極直流送電システムの構成図。FIG. 5 is a configuration diagram of a bipolar DC power transmission system.
【図６】双極直流送電システムにおいて中性点に直流し
ゃ断器を使用した構成図。FIG. 6 is a configuration diagram in which a DC breaker is used at a neutral point in a bipolar DC transmission system.
１，２ 交流母線 ３，３′，４，４′ 変換用変圧器 ５，５′，６，６′ 交直変換器 ７，７′ 直流送電線 ８ 金属帰路線 ９ 接地点 10 中性点 11 地絡事故点 12 直流しゃ断器 13 直流差電流 1, 2 AC bus 3, 3 ', 4, 4' Conversion transformer 5, 5 ', 6, 6' AC / DC converter 7, 7 'DC transmission line 8 Metal return line 9 Ground point 10 Neutral point 11 Ground Fault point 12 DC breaker 13 DC differential current
Claims (1)
おいて、金属帰路線に地絡事故が発生したとき、一方の
極の直流電流を一旦強制的に増加させてから減少させる
ことにより、各極夫々の直流電流が同一となる点を強制
的につくり出す制御機能を具備したことを特徴とする直
流送電設備。1. In a bipolar DC power transmission system having a neutral line, when a ground fault occurs on a metal return line, the DC current of one pole is forcibly increased once and then decreased, thereby A DC power transmission facility having a control function for forcibly creating points where the DC currents of the respective poles are the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3301493A JPH05146062A (en) | 1991-11-18 | 1991-11-18 | Dc transmisstion facility |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3301493A JPH05146062A (en) | 1991-11-18 | 1991-11-18 | Dc transmisstion facility |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05146062A true JPH05146062A (en) | 1993-06-11 |
Family
ID=17897582
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3301493A Pending JPH05146062A (en) | 1991-11-18 | 1991-11-18 | Dc transmisstion facility |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05146062A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104977474A (en) * | 2014-04-14 | 2015-10-14 | Ls产电株式会社 | System for measuring transmission loss in a hvdc system |
| CN112290520A (en) * | 2020-11-13 | 2021-01-29 | 中国南方电网有限责任公司超高压输电公司昆明局 | Grounding fault protection method for metal return line of three-terminal direct-current power transmission system |
-
1991
- 1991-11-18 JP JP3301493A patent/JPH05146062A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104977474A (en) * | 2014-04-14 | 2015-10-14 | Ls产电株式会社 | System for measuring transmission loss in a hvdc system |
| JP2015203702A (en) * | 2014-04-14 | 2015-11-16 | エルエス産電株式会社Lsis Co., Ltd. | System of measuring damage of hvdc |
| US9733278B2 (en) | 2014-04-14 | 2017-08-15 | Lsis Co., Ltd. | System for measuring loss of HVDC |
| CN112290520A (en) * | 2020-11-13 | 2021-01-29 | 中国南方电网有限责任公司超高压输电公司昆明局 | Grounding fault protection method for metal return line of three-terminal direct-current power transmission system |
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