JPH01198256A - Ground-fault protective device of synchronous generator - Google Patents
Ground-fault protective device of synchronous generatorInfo
- Publication number
- JPH01198256A JPH01198256A JP2205188A JP2205188A JPH01198256A JP H01198256 A JPH01198256 A JP H01198256A JP 2205188 A JP2205188 A JP 2205188A JP 2205188 A JP2205188 A JP 2205188A JP H01198256 A JPH01198256 A JP H01198256A
- Authority
- JP
- Japan
- Prior art keywords
- synchronous generator
- voltage
- harmonic
- generator
- detector
- 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
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 38
- 230000001681 protective effect Effects 0.000 title abstract 3
- 230000007935 neutral effect Effects 0.000 claims abstract description 14
- 238000012544 monitoring process Methods 0.000 abstract 1
- 230000007423 decrease Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 238000010248 power generation Methods 0.000 description 4
- 230000001629 suppression Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Landscapes
- Synchronous Machinery (AREA)
Abstract
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、同期発電機の電機子回路の地絡保護装置に関
するものである。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a ground fault protection device for an armature circuit of a synchronous generator.
(従来の技術)
従来同期発電機の電機子回路の地絡保護装置として種々
のものが適用されている。そのうち接地用変圧器を介し
て抵抗接地を行うような大容量発電機の場合、地絡過電
圧継電器によるのが一般的な方式である。この方式では
、同期発電機の電機子回路の中性点近傍の地絡に対して
は検出感度の制約及び外部系統での地絡による移行電圧
との兼ね合いから保護の盲点となっている。しかし、発
電機損傷に及ぼす地絡事故の影響は極めて大きく、その
ため同期発電機の中性点近傍の地絡保護として同期発電
機の中性点を常時環流する第3高調波を利用し、この第
3高調波の不足電圧により検出・保護する方式が近年採
用されている。(Prior Art) Various types of earth fault protection devices have conventionally been applied to the armature circuit of a synchronous generator. In the case of large-capacity generators that are grounded by resistance via a grounding transformer, the common method is to use a ground fault overvoltage relay. In this method, a ground fault near the neutral point of the armature circuit of a synchronous generator is a blind spot in protection due to limitations in detection sensitivity and a balance with transition voltage due to a ground fault in an external system. However, the influence of ground faults on generator damage is extremely large, so the third harmonic that constantly circulates through the neutral point of the synchronous generator is used to protect the ground fault near the neutral point of the synchronous generator. In recent years, a method of detecting and protecting by undervoltage of the third harmonic has been adopted.
これは同期発電機の中性点の第3高調波電圧が負荷電流
に大略比例することを利用し、負荷電流による抑制をつ
け、実測による第3高調波電圧のに倍(kく1、例えば
0.7)を動作値とする様な第3高調波不足電圧による
方式としている。This takes advantage of the fact that the third harmonic voltage at the neutral point of a synchronous generator is roughly proportional to the load current, and suppresses it by the load current, multiplying the actually measured third harmonic voltage by (k x 1, e.g. The method uses a third harmonic undervoltage with an operating value of 0.7).
(発明が解決しようとする課題)
しかしながら通常実測されるのは同期発電機の定格力率
近傍での第3高調波電圧であり、同期発電機の一般的な
特性として、力率が低下すればこの第3高調波電圧も低
下する傾向にある。従って同期発電機の中性点の第3高
調波電圧の不足電圧による検出だけでは例えば系統側の
外部要因によって同期発電機の力率が極端に低下するよ
うな場合にも地絡保護装置が動作する恐れがあり、不必
要に発電プラントの運転員の負担を増加させることにな
る。(Problem to be solved by the invention) However, what is usually actually measured is the third harmonic voltage near the rated power factor of a synchronous generator, and as a general characteristic of a synchronous generator, if the power factor decreases, This third harmonic voltage also tends to decrease. Therefore, if the undervoltage of the third harmonic voltage at the neutral point of the synchronous generator is detected alone, the earth fault protection device will operate even if the power factor of the synchronous generator is extremely reduced due to an external factor on the grid side, for example. This may unnecessarily increase the burden on power plant operators.
本発明は上記の事情を諾みてなされたもので、系統側の
外部要因によって生じる従来の地絡保護装置の不要動作
を防止し発電プラントの安定した運転継続を維持出来る
同期発電機の地絡保護装置を堤供することを目的とする
。The present invention has been made in consideration of the above circumstances, and is a ground fault protection for synchronous generators that prevents unnecessary operation of conventional ground fault protection devices caused by external factors on the grid side and maintains stable continuous operation of power generation plants. The purpose is to provide equipment.
(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の同期発電機の地絡保護
装置は、同期発電機の中性点の第3高調波の不足電圧要
素に加え、同期発電機の主回路に接続され発電機端子電
圧の低下により動作する電圧検出器と発電機力率の低下
により動作する力率検出器とを備えた構成とする。(Means for Solving the Problems) In order to achieve the above object, the synchronous generator ground fault protection device of the present invention provides a The configuration includes a voltage detector that is connected to the main circuit of the generator and operates when the generator terminal voltage decreases, and a power factor detector that operates when the generator power factor decreases.
(作 用)
本発明は以上のように構成されているので、系統側の外
部要因により同期発電機の中性点の第3窩調波電圧が低
下し第3高調波不足電圧要素が動作しても、該発電機の
端子電圧が低下もしくは力率が低下している場合すなわ
ち電圧検出器或いは力率検出器が動作する場合には地絡
保護装置は動作せず不要動作を防止することができる。(Function) Since the present invention is configured as described above, the third harmonic voltage at the neutral point of the synchronous generator decreases due to an external factor on the grid side, and the third harmonic undervoltage element operates. However, if the terminal voltage of the generator decreases or the power factor decreases, that is, if the voltage detector or power factor detector operates, the earth fault protection device will not operate and unnecessary operation can be prevented. can.
(実 施 例)
以下本発明の一実施例を図面を参照して説明する。第1
図は、本発明の一実施例に係る同期発電機の地絡保護装
置の構成を示すブロック図であり、同期発電機1の中性
点回路は接地変圧器2を介して接地されている。接地変
圧器2の2次回路には接地抵抗器3と第3高調波不足電
圧要素4が接続されている。(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing the configuration of a ground fault protection device for a synchronous generator according to an embodiment of the present invention, in which a neutral point circuit of a synchronous generator 1 is grounded via a grounding transformer 2. A grounding resistor 3 and a third harmonic undervoltage element 4 are connected to the secondary circuit of the grounding transformer 2.
一方、同期発電機1の電機子側は発電機主回路5に接続
され、同期発電機1の端子電圧を検出する計器用変圧器
7の2次側は発電機端子電圧の低下を検出する電圧検出
器8に入力される。また、同期発電機1の負荷電流を検
出する計器用変流器6を介して同期発電機1の力率低下
を検出する力率検出器9が接続されている。この力率検
出器9には、当然端子電圧成分として計器用変流器7の
2次出力が入力される。また第3高調波不足電圧要素4
には、負荷電流■Lによる抑制のため計器用変流器6の
出力も入力される。On the other hand, the armature side of the synchronous generator 1 is connected to the generator main circuit 5, and the secondary side of the instrument transformer 7 that detects the terminal voltage of the synchronous generator 1 has a voltage that detects a drop in the generator terminal voltage. It is input to the detector 8. Further, a power factor detector 9 that detects a decrease in the power factor of the synchronous generator 1 is connected via an instrument current transformer 6 that detects the load current of the synchronous generator 1 . Naturally, the secondary output of the instrument current transformer 7 is input to the power factor detector 9 as a terminal voltage component. Also, the third harmonic undervoltage element 4
The output of the meter current transformer 6 is also inputted to the current transformer 6 for suppression by the load current ■L.
次に上記のように構成された本発明の作用について第1
図に破線で示した地絡保護装置10の制御・操作ブロッ
ク図である第2図により説明する。Next, a first explanation of the operation of the present invention configured as described above will be explained.
This will be explained with reference to FIG. 2, which is a control/operation block diagram of the ground fault protection device 10 indicated by broken lines in the figure.
ます地絡故障がなく同期発電機1が正常運転状態にある
場合には、第3高調波不足電圧要素4がが不動作である
ので地絡保護装置10は動作しない。If there is no ground fault and the synchronous generator 1 is in a normal operating state, the third harmonic undervoltage element 4 is inoperative, so the ground fault protection device 10 does not operate.
この様な状態にあるとき、例えば近傍の電源脱落などに
より系統電圧が著しく低下し同期発電機1の端子電圧も
異常に低下する様な場合、図示しないが同期発電機1の
励磁装置の動作により界磁電流が急増し発電機の力率は
著しく低下する。In such a situation, for example, if the grid voltage drops significantly due to a power outage in the vicinity, and the terminal voltage of the synchronous generator 1 also drops abnormally, the operation of the excitation device of the synchronous generator 1 (not shown) The field current increases rapidly and the power factor of the generator drops significantly.
ここで、同期発電機1の運転状態と第3高調波電圧CV
3t) の関係は、一般に第3図に示す如く同期発電
機の負荷電流(It、)及び力率に依存している。Here, the operating state of the synchronous generator 1 and the third harmonic voltage CV
3t) generally depends on the load current (It, ) and power factor of the synchronous generator, as shown in FIG.
従って前述の状態では第3高調波不足電圧要素4は負荷
電流にもよるが動作する恐れがある。Therefore, in the above-mentioned state, the third harmonic undervoltage element 4 may operate depending on the load current.
しかしこのような場合には、第2図に示すように電圧検
出器8もしくは力率検出器9が動作するため地絡保護装
置10は動作に至ることはない。However, in such a case, the voltage detector 8 or the power factor detector 9 operates as shown in FIG. 2, so the earth fault protection device 10 does not operate.
また、同期発電機1の中性点近傍で地絡が発生した場合
には第3高調波不足電圧要素4が本来の正常動作を行う
が、電圧検出器8および力率検出器9は状態の変化が殆
んどなく不動作のため、地絡保護装置10は正常に動作
する。Furthermore, when a ground fault occurs near the neutral point of the synchronous generator 1, the third harmonic undervoltage element 4 operates normally, but the voltage detector 8 and power factor detector 9 Since there is almost no change and no operation occurs, the ground fault protection device 10 operates normally.
従って、本実施例によれば従来の同期発電機1の中性点
近傍の地絡保護として第3高調波不足電圧要素4のみに
よる場合の系統側の外部要因によって生じる不要な動作
を防止し、本来の地絡事故時にのみ動作させることが出
来る。Therefore, according to this embodiment, unnecessary operations caused by external factors on the grid side when only the third harmonic undervoltage element 4 is used as ground fault protection near the neutral point of the conventional synchronous generator 1 are prevented, It can only be activated in the event of an actual ground fault.
即ち発電プラントの不要な非常停止に伴う波及効果や不
要な警報に伴う発電プラントの運転員への負担増などを
防ぐことが出来る。In other words, it is possible to prevent the ripple effects caused by unnecessary emergency stoppage of the power generation plant and the increased burden on the power generation plant operators caused by unnecessary alarms.
(他の実施例)
尚、本発明は上記実施例に限定されるものではない。例
えば、
■ 上記実施例では第2図に示す如く、地絡保護装置の
動作条件として電圧検出器8と力率検出器9の両方の不
動作条件を考慮しているがどちらか一方の構成による不
動作条件によっても上記実施例と同様の効果が得られる
。(Other Examples) Note that the present invention is not limited to the above embodiments. For example, (1) In the above embodiment, as shown in FIG. 2, the non-operating condition of both the voltage detector 8 and the power factor detector 9 is considered as the operating condition of the ground fault protection device, but the configuration of either one Even under non-operating conditions, the same effects as in the above embodiment can be obtained.
■ また第3高調波不足電圧要素4の負荷電流による抑
制回路を上記電圧検出器8もしくは力率検出器9が動作
した場合に除去(例えば計器用変流器6からの入力回路
を短絡)するようにして、第3図に示した第3高調波不
足電圧要素4の特性を負荷電流に依存しない一定値(I
L=Oの値に固定)とすることによっても上記実施例と
同様の効果を得ることができる。■ Also, the suppression circuit due to the load current of the third harmonic undervoltage element 4 is removed when the voltage detector 8 or power factor detector 9 is activated (for example, by short-circuiting the input circuit from the instrument current transformer 6). In this way, the characteristics of the third harmonic undervoltage element 4 shown in FIG. 3 are set to a constant value (I
The same effect as in the above embodiment can also be obtained by fixing the value L=O.
以上述べたように本発明は発電機の端子電圧及び力率の
変化を監視・検出することにより、系統側の外部要因に
よって生じる従来の第3高調波不足電圧要素による地絡
保護装置の不要動作を防止し、発電プラントの安定した
運転継続を維持出来る同期発電機の地絡保護装置を提供
することが出来る。As described above, the present invention monitors and detects changes in the terminal voltage and power factor of the generator, thereby preventing unnecessary operation of the ground fault protection device due to the conventional third harmonic undervoltage element caused by external factors on the grid side. Therefore, it is possible to provide a ground fault protection device for a synchronous generator that can prevent this and maintain stable continuous operation of a power generation plant.
第1図は、本発明の一実施例に係る同期発電機の地絡保
護装置の構成を示すブロック図、第2図は第1図に示し
た同期発電機の地絡保護装置の作用を説明するための制
御・操作ブロック図、第3図は、同期発電機の中性点の
第3高調波電圧の特性を示す図である。
1・・・同期発電機
4・・・第3高調波不足電圧要素
8・・・電圧検出器 9・・・力率検出器10・
・・地絡保護装置
代理人 弁理士 則 近 憲 佑
同 第子丸 健
第2図
第3図Fig. 1 is a block diagram showing the configuration of a ground fault protection device for a synchronous generator according to an embodiment of the present invention, and Fig. 2 explains the operation of the ground fault protection device for a synchronous generator shown in Fig. 1. FIG. 3 is a control/operation block diagram showing the characteristics of the third harmonic voltage at the neutral point of the synchronous generator. 1... Synchronous generator 4... Third harmonic undervoltage element 8... Voltage detector 9... Power factor detector 10.
...Earth fault protection device agent Patent attorney Nori Chika Ken Yudo Ken Daishimaru Figure 2 Figure 3
Claims (1)
高調波不足電圧要素にて行う同期発電機の地絡保護装置
において、 前記発電機の主回路に接続され、発電機端子電圧の低下
により動作する電圧検出器と発電機力率の低下により動
作する力率検出器とを備えていることを特徴とする同期
発電機の地絡保護装置。 2、中性点の第3高調波不足電圧要素が動作し、前記電
圧検出器と前記力率検出器が共に不動作のときに動作す
ることを特徴とする特許請求の範囲第1項記載の同期発
電機の地絡保護装置。[Claims] 1. Earth fault protection near the neutral point of the armature circuit
A ground fault protection device for a synchronous generator using a harmonic undervoltage element includes a voltage detector connected to the main circuit of the generator and activated by a drop in generator terminal voltage, and a voltage detector activated by a drop in generator power factor. A ground fault protection device for a synchronous generator, characterized by comprising a power factor detector. 2. The third harmonic undervoltage element at the neutral point operates and operates when both the voltage detector and the power factor detector are inoperative. Ground fault protection device for synchronous generators.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2205188A JPH01198256A (en) | 1988-02-03 | 1988-02-03 | Ground-fault protective device of synchronous generator |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2205188A JPH01198256A (en) | 1988-02-03 | 1988-02-03 | Ground-fault protective device of synchronous generator |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH01198256A true JPH01198256A (en) | 1989-08-09 |
Family
ID=12072121
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2205188A Pending JPH01198256A (en) | 1988-02-03 | 1988-02-03 | Ground-fault protective device of synchronous generator |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH01198256A (en) |
-
1988
- 1988-02-03 JP JP2205188A patent/JPH01198256A/en active Pending
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