JPS63274322A - Zero-phase current transformer - Google Patents
Zero-phase current transformerInfo
- Publication number
- JPS63274322A JPS63274322A JP10474887A JP10474887A JPS63274322A JP S63274322 A JPS63274322 A JP S63274322A JP 10474887 A JP10474887 A JP 10474887A JP 10474887 A JP10474887 A JP 10474887A JP S63274322 A JPS63274322 A JP S63274322A
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- Japan
- Prior art keywords
- zero
- current transformer
- phase
- optical
- waveform
- 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.)
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Links
- 230000003287 optical effect Effects 0.000 claims abstract description 32
- 238000012937 correction Methods 0.000 claims abstract description 11
- 238000012935 Averaging Methods 0.000 claims description 10
- 238000004804 winding Methods 0.000 claims description 10
- 230000000694 effects Effects 0.000 claims description 8
- 239000013307 optical fiber Substances 0.000 claims description 8
- 238000005259 measurement Methods 0.000 claims description 5
- 230000005697 Pockels effect Effects 0.000 claims description 2
- 238000012545 processing Methods 0.000 abstract description 18
- 238000005070 sampling Methods 0.000 abstract description 7
- 238000010586 diagram Methods 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 230000007257 malfunction Effects 0.000 description 4
- 230000004907 flux Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 241001562081 Ikeda Species 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
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Abstract
Description
【発明の詳細な説明】
[産業上の利用分野]
この発明は、地絡事故発生時に流れる零相電流を検出す
るために高圧の3相配電線に設置される零相変流器に関
し、特に軽量且つ安全な零相変流器に関するものである
。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a zero-phase current transformer that is installed in a high-voltage three-phase distribution line to detect zero-sequence current that flows when a ground fault occurs. The present invention also relates to a safe zero-phase current transformer.
[従来の技術]
第5図は、例えば「計器用変成器」(電気書院、池田三
穂司著)の第79頁に記載された、従来の零相変流器を
示す構成図である。[Prior Art] FIG. 5 is a configuration diagram showing a conventional zero-phase current transformer, which is described, for example, on page 79 of "Instrument Transformer" (Denki Shoin, authored by Mihoji Ikeda).
図において、(1a)〜(1c)は3相配電線、(2)
は3相配電線(1a)〜(1c)を包囲するように設け
られた1つの環状鉄心、(3)は環状鉄心(2)の一部
に巻回された二次巻線、(4)は二次巻線(3)の両端
間に接続された地絡検出リレー等の二次負担である。In the figure, (1a) to (1c) are three-phase distribution lines, (2)
is one annular core provided to surround the three-phase distribution lines (1a) to (1c), (3) is a secondary winding wound around a part of the annular core (2), and (4) is a This is a secondary load such as a ground fault detection relay connected between both ends of the secondary winding (3).
次に、第5図に示した従来の零相変流器の動作について
説明する。Next, the operation of the conventional zero-phase current transformer shown in FIG. 5 will be explained.
定常時においては、3相配電線(Ia)〜(fc)の各
相を流れる電流は、正相分と逆相骨のみである。During steady state, the current flowing through each phase of the three-phase distribution lines (Ia) to (fc) is only the positive phase portion and the negative phase portion.
このとき、環状鉄心(2)は、各相の正相分及び逆相骨
の電流に比例した各磁界を合成した磁界によって誘起さ
れるため、環状鉄心(2)中の磁束は零である。従って
、二次巻線(3)には電流が流れず、二次負担(4)は
動作しない。At this time, the annular iron core (2) is induced by a magnetic field that is a composite of the magnetic fields proportional to the positive-phase components of each phase and the negative-phase bone currents, so the magnetic flux in the annular iron core (2) is zero. Therefore, no current flows through the secondary winding (3) and the secondary load (4) does not operate.
一方、3相配電線(1a)〜(IC)のいずれかに地絡
事故が発生すると、各相分の電流を合成しても零になら
ず、零相電流が流れる。従って、環状鉄心(2)中に磁
束が誘起されて二次巻線(3)に零fll?11流に比
例した二次電流が流れ、二次負担(4)が動作する。On the other hand, when a ground fault occurs in any of the three-phase distribution lines (1a) to (IC), the currents for each phase do not become zero even if they are combined, and a zero-phase current flows. Therefore, magnetic flux is induced in the annular core (2) and zero in the secondary winding (3). A secondary current proportional to the current flows, and the secondary load (4) operates.
一般に、この種の零相変流器は変電所の構内に設置され
ており、地絡事故が発生した場合、二次負担(4)によ
り3相配電線(la)〜(lc)を切離して事故の拡大
を防いでいる。しかし、地絡事故が発生した場合でも、
できるだけ停電区間を限定し且つ復旧時間を短くするた
め、事故点を早期に正確に発見する手段が要求されてい
る。このため、零相変流器を、変電所構内ばかりでなく
3相配電線(1a)〜(1c)の途中(屋外の配電柱)
に多数個設置することが必要になってきている。Generally, this type of zero-phase current transformer is installed within the premises of a substation, and if a ground fault occurs, the secondary burden (4) will disconnect the three-phase distribution lines (LA) to (LC) and prevent the accident. prevents the expansion of However, even if a ground fault occurs,
In order to limit the power outage section and shorten the restoration time as much as possible, a means to quickly and accurately discover the point of failure is required. For this reason, zero-phase current transformers are installed not only inside substations, but also in the middle of three-phase distribution lines (1a) to (1c) (outdoor distribution poles).
It has become necessary to install a large number of them.
[発明が解決しようとする問題点]
従来の零相変流器は以上のように、3相配電線(1a)
〜(1c)を一括して包囲する環状鉄心(2)を用いて
、地絡事故による3相配電線(1a)〜(1c)の零相
電流を検出しているので、屋外の配電柱に設置する場合
に大形になり、又、落雷等により事故が拡大するという
問題点があった。[Problems to be solved by the invention] As described above, the conventional zero-phase current transformer is connected to the three-phase distribution line (1a)
Since the zero-sequence current of the three-phase distribution lines (1a) to (1c) due to a ground fault is detected by using the ring core (2) that encloses ~ (1c) all at once, it is installed on an outdoor distribution pole. In addition, there were problems in that it became large and accidents were amplified due to lightning strikes, etc.
又、このような問題点を解決するため、軽量で絶縁信頼
性の高い光変流器を用いて各相の電流を個別に検出し、
零相電流を合成して検出することも考えられているが、
各光変流器の温度特性の違いなどにより、二次負担(4
)が誤動作するという問題点があった。In addition, in order to solve these problems, the current of each phase is detected individually using a lightweight optical current transformer with high insulation reliability.
It has also been considered to synthesize and detect zero-sequence currents, but
Due to differences in temperature characteristics of each optical current transformer, secondary burden (4
) had the problem of malfunctioning.
この発明は上記のような問題点を解決するためになされ
たもので、光変流器を用いて零相電流を合成することに
より、軽量で、しかも事故の拡大や誘発する恐れのない
零相変流器を得ることを目的とする。This invention was made in order to solve the above-mentioned problems, and by combining zero-sequence currents using an optical current transformer, it is possible to create a zero-sequence current that is lightweight and does not cause the spread or trigger of an accident. The purpose is to obtain a current transformer.
[問題点を解決するための手段]
この発明に係る零相変流器は、所定期間毎の零相電流成
分を平均化した平均波形を演算し、次の平均処理期間が
終了した後の零相電流成分から平均波形を減算した波形
を出力するための補正演算回路を設けたものである。[Means for Solving the Problems] The zero-phase current transformer according to the present invention calculates an average waveform obtained by averaging zero-sequence current components for each predetermined period, and calculates the average waveform of zero-sequence current components after the next averaging period ends. A correction calculation circuit is provided to output a waveform obtained by subtracting the average waveform from the phase current component.
[作用]
この発明においては、各光変流器などの温度特性差によ
る零相電流成分は零になるように補正し、地絡事故によ
る零相電流成分はそのまま出力するようして二次負担の
誤動作を防ぐ。[Function] In this invention, the zero-sequence current component due to the temperature characteristic difference of each optical current transformer is corrected to zero, and the zero-sequence current component due to a ground fault is output as is, thereby reducing the secondary burden. prevent malfunction.
[実施例コ
以下、この発明の一実施例を図について説明する。第1
図はこの発明の一実施例を示すブロック図であり、(1
a)〜(IC)は前述と同様のものである。[Example 1] An example of the present invention will be described below with reference to the drawings. 1st
The figure is a block diagram showing one embodiment of the present invention.
a) to (IC) are the same as described above.
(2&)〜(2C)は空隙を有する3つの環状鉄心であ
り、各環状の中心部を3相配電線(1a)〜(IC)が
個別に貫通するように配設されている。(5a)〜(5
C)は各環状鉄心(2a)〜(2c)の空隙に配置され
たファラデー効果を用いた光磁界センサ、(6a)〜(
6C)は各光磁界センサ(5a)〜(5c)に光を供給
する発光素子、(7a)〜(7c)は各光磁界センサ(
5a)〜(5C)からの光を検知する受光素子、(8a
)〜(8C)は発光素子(6a)〜(6C)及び受光素
子(7a)〜(7C)を各光磁界センサ(5b)〜(5
C)に接続する導光用の光ファイバであり、これらは環
状鉄心(2a)〜〈2C)と共に光変流器を構成してい
る。(2&) to (2C) are three annular cores having voids, and three-phase distribution lines (1a) to (IC) are arranged so as to individually pass through the center of each annular core. (5a) - (5
C) is an optical magnetic field sensor using the Faraday effect arranged in the air gap of each annular core (2a) to (2c), (6a) to (
6C) is a light emitting element that supplies light to each magneto-optical field sensor (5a) to (5c), and (7a) to (7c) is a light emitting element that supplies light to each magneto-optical field sensor (5a) to (5c).
a light-receiving element that detects light from 5a) to (5C), (8a
) to (8C) connect the light emitting elements (6a) to (6C) and the light receiving elements (7a) to (7C) to each of the optical magnetic field sensors (5b) to (5).
It is an optical fiber for light guiding connected to C), and together with the annular cores (2a) to <2C), these constitute an optical current transformer.
(9a)〜(9C)は各受光素子(7a)〜(7C)か
らの信号が個別に入力される信号処理回路、(10)は
各信号処理回路(9a)〜(9C)からの信号を加算す
る加算回路、(11)は加算回路(10)からの信号を
補正するための補正演算回路であり、これらは計測回路
(12)を構成している。(9a) to (9C) are signal processing circuits into which signals from each light receiving element (7a) to (7C) are individually input, and (10) is a signal processing circuit to which signals from each signal processing circuit (9a) to (9C) are input. The addition circuit (11) for addition is a correction calculation circuit for correcting the signal from the addition circuit (10), and these constitute a measurement circuit (12).
又、図示しないが、計測回路(12)の出力端子には、
第5図と同様の二次負担(4)が接続されている。Although not shown, the output terminal of the measurement circuit (12) is
A secondary load (4) similar to that in FIG. 5 is connected.
次に、第1図に示したこの発明の一実施例の動作につい
て説明する。Next, the operation of the embodiment of the present invention shown in FIG. 1 will be explained.
まず、環状鉄心(2a)〜(2c)は、3相配電線(1
a)〜(IC)を流れる電流ににより、各電流に比例し
た磁界が誘起される。First, the annular iron cores (2a) to (2c) are connected to the three-phase distribution line (1
The currents flowing through a) to (IC) induce a magnetic field proportional to each current.
このとき、発光素子(6a)〜(6C)から光ファイノ
く(8a)〜(8C)を介して光磁界センサ(5a)〜
(5C)に達した光は、環状鉄心(2a)〜(2C)の
各空隙中の磁界に比例して変調を受け、ファラデー効果
により偏光面が回転する。At this time, the light emitting elements (6a) to (6C) are connected to the optical magnetic field sensors (5a) to
The light reaching (5C) is modulated in proportion to the magnetic field in each gap of the annular iron cores (2a) to (2C), and the plane of polarization is rotated by the Faraday effect.
こうして光磁界センサ(5a)〜(5C)により変調を
受けた光は、光ファイバ(8a)〜(8C)を介して受
光素子(7a)〜(7C)に検知され、磁界に比例した
信号に変換される。The light modulated by the optical magnetic field sensors (5a) to (5C) is detected by the light receiving elements (7a) to (7C) via the optical fibers (8a) to (8C), and converted into a signal proportional to the magnetic field. converted.
更に、受光素子(7a)〜(7C)で電気変換された信
号は、信号処理回路(9a)〜(9C)により3相配電
線(1a)〜(1c)を流れる電流に比例した電流信号
に変換され、加算回路(10)により加算される。Furthermore, the signals electrically converted by the light receiving elements (7a) to (7C) are converted into current signals proportional to the current flowing through the three-phase distribution lines (1a) to (1c) by signal processing circuits (9a) to (9C). and are added by an adder circuit (10).
定常時においては、3相配電線(1a)〜(IC)の各
電流を合成すると零になるため、加算回路(10)の出
力信号も零となる。In a steady state, the sum of the currents of the three-phase distribution lines (1a) to (IC) becomes zero, so the output signal of the adder circuit (10) also becomes zero.
一方、3相配電線(IC)〜(1a)に地絡事故が発生
した場合は、各電流を合成しても零にならない零相電流
が流れるため、加算回路(10)の出力信号は零相電流
に比例した値となり、3相配電線(1a)〜(1c)の
地絡事故を検出することができる。On the other hand, if a ground fault occurs in the three-phase distribution line (IC) to (1a), a zero-phase current will flow that does not become zero even when the currents are combined, so the output signal of the adder circuit (10) will be zero-phase. The value is proportional to the current, and ground faults in the three-phase distribution lines (1a) to (1c) can be detected.
しかし、実際には、光磁界センサ(5a)〜(5c)及
び信号処理回路(9a)〜(9c)が温度特性を持って
おり、しかも、個々の温度特性に差があるのが普通であ
る。従って、3相配電線(1a)〜(IC)の各電流と
信号処理回路(9a)〜(9c)からの各電流信号との
比率は、周囲温度の変化により各相間に差を生じる。こ
のため、加算回路(10)の出力信号は、3相配電線(
1a)〜(1c)に零相電流が流れていないときでも零
にならず、二次負担(4)が誤動作する原因となる。However, in reality, the optical magnetic field sensors (5a) to (5c) and the signal processing circuits (9a) to (9c) have temperature characteristics, and it is normal that the temperature characteristics of each individual are different. . Therefore, the ratio of each current in the three-phase distribution lines (1a) to (IC) to each current signal from the signal processing circuits (9a) to (9c) varies between the phases due to changes in ambient temperature. Therefore, the output signal of the adder circuit (10) is
Even when zero-sequence current is not flowing in 1a) to (1c), it does not become zero, causing the secondary load (4) to malfunction.
補正演算回路(11)は、上記のような誤動作を防ぐた
めのものであり、例えばマイクロプロセッサから構成さ
れ、3つの光磁界センサ(5a)〜(5c)及び信号処
理回路(9a)〜(9c)の温度特性の差によって生じ
る零相電流成分のみを常に零に補正演算するようになっ
ている。即ち、温度特性の差による零相電流成分は周囲
温度の変化によって生じるため変化がゆるやかであるの
に対し、地絡事故による零相電流成分は事故発生と同時
に瞬時に生じるため変化が急激であることに着目し、第
2図のフローチャート図に従って補正演算を行う。The correction calculation circuit (11) is for preventing malfunctions as described above, and is composed of, for example, a microprocessor, and includes three optical magnetic field sensors (5a) to (5c) and signal processing circuits (9a) to (9c). ), only the zero-sequence current component caused by the difference in temperature characteristics between the two is always corrected to zero. In other words, the zero-sequence current component due to differences in temperature characteristics is caused by changes in the ambient temperature and therefore changes slowly, whereas the zero-sequence current component due to a ground fault occurs instantaneously at the same time as the fault occurs, so the change is rapid. Focusing on this, correction calculations are performed according to the flowchart shown in FIG.
まず、正弦波形からなる加算回路(10)の出力信号を
、例えば1周期の30°毎に分割してサンプリングを行
う(ステップsi)。First, the output signal of the adder circuit (10) having a sine waveform is divided and sampled, for example, every 30 degrees of one cycle (step si).
これにより、1周期毎に正弦波形を再現する12個の信
号が得られる。又、このときのサンプリング周期は出力
波形の30°毎に限らず、演算処理速度が高速化できる
場合は30”以下に細分化してもよく、逆に高い精度が
要求されない場合は30°以上にいIn<してもよい。As a result, 12 signals reproducing a sine waveform are obtained every cycle. Also, the sampling period at this time is not limited to every 30° of the output waveform, but may be subdivided into 30" or less if the calculation processing speed can be increased, or conversely, if high precision is not required, the sampling period may be divided into 30" or more. In< may be used.
次に、所定期間中にサンプリングにより得られた信号を
各分割成分毎に平均して、正弦波形からなる平均波形を
作成する(ステップS2)。Next, the signals obtained by sampling during a predetermined period are averaged for each divided component to create an average waveform consisting of a sine waveform (step S2).
このときの所定期間は、二次負担〈4)が動作する時間
(通常、0.1〜0.5秒)に合わせて、0.1秒以上
の適宜の時間に設定される。The predetermined period at this time is set to an appropriate time of 0.1 seconds or more in accordance with the time during which the secondary burden (4) operates (usually 0.1 to 0.5 seconds).
次に、こうして得られた平均波形を次の処理期間記憶し
くステップS3)、次の平均処理期間終了後に、加算回
路(10)の出力信号の波形から前回記憶された平均波
形を減算する(ステップs4)。Next, the average waveform thus obtained is stored for the next processing period (step S3), and after the end of the next average processing period, the previously stored average waveform is subtracted from the waveform of the output signal of the adder circuit (10) (step S3). s4).
即ち、今回得られた加算回路(1o)の出方波形から前
回演算された平均波形を減算する。このとき、同時に今
回の出力波形の平均処理も行なわれ、次回の減算に用い
られる平均波形が記憶される。従って、所定期間毎の零
相電流成分を平均化した平均波形を演算し、次の平均処
理期間が終了した後の零相電流成分から平均波形を減算
した波形を出方することになる。That is, the average waveform computed last time is subtracted from the output waveform of the adder circuit (1o) obtained this time. At this time, the current output waveform is also averaged at the same time, and the average waveform used for the next subtraction is stored. Therefore, an average waveform obtained by averaging the zero-sequence current components for each predetermined period is calculated, and a waveform obtained by subtracting the average waveform from the zero-sequence current component after the next averaging processing period ends is output.
このように、加算回路(10)の出力信号のサンプリン
グ波形信号から前回演算された平均波形を減算すること
により、周囲温度によって徐々に変化する零相電流成分
に対しては、補正演算回路(11)の出力信号が常に零
又は二次負担(4)の動作レベルより十分率さい値に補
正される。In this way, by subtracting the previously calculated average waveform from the sampling waveform signal of the output signal of the adder circuit (10), the correction calculation circuit (11 ) is always corrected to zero or a value sufficiently lower than the operating level of secondary burden (4).
一方、地絡事故によって零相電流が急激に変化する場合
は、平均処理期間、即ち少なくとも二次負担(4)が動
作する時間以上は減算処理が行なわれないため、零相電
流成分がそのまま補正演算回路(11)から出力される
0例えば、成る平均処理期間の終了直前に地絡事故が発
生して加算回路(10)の出力信号に零相電流成分が生
じたとすると、次の平均処理期間中(所定期間)は減算
処理されず、二次負担(4)が動作するのに十分な時間
に亘って零相電流成分が出力される。従って、確実に地
絡事故を検出して二次負担(4)を動作させ、3相配電
線(1a)〜(1c)を切離すことができる。On the other hand, if the zero-sequence current changes suddenly due to a ground fault, the subtraction process is not performed during the average processing period, that is, at least the time during which the secondary burden (4) operates, so the zero-sequence current component is corrected as is. For example, if a ground fault occurs just before the end of the averaging processing period, and a zero-sequence current component occurs in the output signal of the adding circuit (10), then the next averaging processing period During the middle (predetermined period), the subtraction process is not performed, and the zero-sequence current component is output for a time sufficient for the secondary load (4) to operate. Therefore, it is possible to reliably detect a ground fault, operate the secondary load (4), and disconnect the three-phase distribution lines (1a) to (1c).
尚、上記実施例では補正演算回部(11)を加算回路(
10)と別々に構成したが、これらを一体化し、加算及
び補正演算を同時に行うマイクロプロセッサで楕成して
もよい。In the above embodiment, the correction calculation circuit (11) is replaced by an addition circuit (
10), but they may be integrated and configured using a microprocessor that simultaneously performs addition and correction operations.
又、光変流器を、空隙を有する環状鉄心(2a)〜(2
c)と、各空隙に配置されたファラデー効果を用いた光
磁界センサ(5a)〜(5c)とにより構成した場合に
ついて説明したが、第3図に示すように、環状鉄心(2
a)〜(2c)の一部にそれぞれ巻回された巻線(13
m)〜(13c)と、これら巻線(13a)〜(13c
)の各両端間に接続された抵抗器(14a)〜(14e
)と、これら抵抗器(14a)〜(14c)にそれぞれ
に並列接続され各抵抗器(14a)〜(14c)の両端
間の電圧を計測するためのポッケルス効果を用いた光電
圧センサ(15a)〜(15c)とにより楕成してもよ
い、ここで、図示しない部分は第1図と同様の構成であ
る。In addition, the optical current transformer is made of annular cores (2a) to (2) having voids.
c) and optical magnetic field sensors (5a) to (5c) using the Faraday effect placed in each gap, but as shown in FIG.
Winding wires (13) each wound around a part of a) to (2c)
m) to (13c) and these windings (13a) to (13c
) are connected across the resistors (14a) to (14e
), and an optical voltage sensor (15a) connected in parallel to these resistors (14a) to (14c) and using the Pockels effect to measure the voltage across each resistor (14a) to (14c). ~(15c) may be formed into an ellipse. Here, the portions not shown have the same structure as in FIG. 1.
この場合、3相配電線(1a)〜(1c)の−次側電流
に比例した二次側電流を巻線(13m)〜(13e)に
より取得し、これら二次側電流を抵抗器(14a)〜(
14e)により電圧に変換し、光電圧センサ(15m)
〜(15c)によって検出する。In this case, a secondary current proportional to the negative current of the three-phase distribution lines (1a) to (1c) is obtained by the windings (13m) to (13e), and these secondary currents are connected to the resistor (14a). ~(
14e) into voltage, and a photovoltage sensor (15m)
~(15c).
更に、第4図に示すように、ファラデー効果を用いた光
磁界センサ(16a)〜(16c)を環状に楕成し、各
環状中心部に3相配電線(1a)〜(1c)が包囲され
るようにして光変流器を構成してもよい。Furthermore, as shown in FIG. 4, optical magnetic field sensors (16a) to (16c) using the Faraday effect are arranged in an elliptical ring shape, and three-phase power distribution lines (1a) to (1c) are surrounded by the center of each ring. The optical current transformer may be constructed in such a manner that
この場合、光ファイバ(8a)〜(8c)を介して入射
された光は、3相配電線(1a)〜(1c)を巡回して
再び光ファイバ(8a)〜(8c)を介して受光素子(
7a)〜(7c)及び計測回路(12)に入力される。In this case, the light incident through the optical fibers (8a) to (8c) circulates through the three-phase distribution lines (1a) to (1c), and then passes through the optical fibers (8a) to (8c) again to the light receiving element. (
7a) to (7c) and the measurement circuit (12).
従って、各光磁界センサ(16a)〜(16c)は反射
を繰り返すようになっている。Therefore, each of the optical magnetic field sensors (16a) to (16c) repeats reflection.
[発明の効果]
以上のようにこの発明によれば、所定期間毎の零相電流
成分を平均化した平均波形を演算し、次の平均処理期間
が終了した後の零相電流成分から平均波形を減算した波
形を出力するための補正演算回路を設け、各光変流器な
どの温度特性差による零相電流成分は零になるように補
正し、地絡事故による零相電流成分はそのまま出力する
ようしたので、二次負担の誤動作を防ぐことができ、軽
量且つ正確で安全な零相変流器が得られる効果がある。[Effects of the Invention] As described above, according to the present invention, the average waveform obtained by averaging the zero-sequence current components for each predetermined period is calculated, and the average waveform is calculated from the zero-sequence current component after the next averaging processing period ends. A correction calculation circuit is provided to output a waveform obtained by subtracting , and the zero-sequence current component due to differences in temperature characteristics of each optical current transformer is corrected to zero, and the zero-sequence current component due to a ground fault is output as is. As a result, it is possible to prevent malfunction due to the secondary load, and there is an effect that a lightweight, accurate, and safe zero-phase current transformer can be obtained.
第1図はこの発明の一実施例を示すブロック図、第2図
は第1図の動作を説明するためのフローチャート図、第
3図はこの発明の第2実施例の要部を示す構成図、第4
図はこの発明の第3実施例の要 □部を示す構成図、
第5図は従来の零相変流器を示す構成図である。
(1a)〜(1c)・・・3相配電線
(2a)〜(2c)・・・環状鉄心
(5a)〜(5c)・・・光磁界センサ(6a)〜(6
c)・・・発光素子 (7a)〜(7c)・・・受光素
子(8a)〜(8c)・・・光ファイバ
(11)・・・補正演算回路 (12)・・・計測回
路(13a)〜(13c)−・巻線 (14a)〜(
14c)−・抵抗器(15a)〜(15c)・・・光電
圧センサ(16a)〜(16c)・・・光磁界センサ尚
、図中、同一符号は同−又は相当部分を示す。
第1図
第2図
第3図
第4図
12へ
第5図FIG. 1 is a block diagram showing one embodiment of this invention, FIG. 2 is a flowchart for explaining the operation of FIG. 1, and FIG. 3 is a configuration diagram showing the main parts of a second embodiment of this invention. , 4th
The figure is a configuration diagram showing the main part of the third embodiment of this invention,
FIG. 5 is a configuration diagram showing a conventional zero-phase current transformer. (1a) to (1c)... Three-phase distribution line (2a) to (2c)... Annular iron core (5a) to (5c)... Optical magnetic field sensor (6a) to (6
c)...Light emitting element (7a) to (7c)...Light receiving element (8a) to (8c)...Optical fiber (11)...Correction calculation circuit (12)...Measuring circuit (13a) )~(13c)-・Winding (14a)~(
14c) - Resistors (15a) to (15c)... Optical voltage sensors (16a) to (16c)... Optical magnetic field sensor In the drawings, the same reference numerals indicate the same or corresponding parts. Figure 1 Figure 2 Figure 3 Figure 4 To 12 Figure 5
Claims (5)
光変流器と、これら光変流器からの信号を合成して零相
電流成分を検出する計測回路とを備えた零相変流器にお
いて、前記計測回路は、所定期間毎の零相電流成分を平
均化した平均波形を演算し、次の平均処理期間が終了し
た後の零相電流成分から前記平均波形を減算した波形を
出力するための補正演算回路を含むことを特徴とする零
相変流器。(1) A zero-phase system equipped with three optical current transformers that individually measure the current in each phase of a three-phase distribution line, and a measurement circuit that combines the signals from these optical current transformers and detects the zero-phase current component. In the phase current transformer, the measurement circuit calculates an average waveform by averaging the zero-sequence current components for each predetermined period, and subtracts the average waveform from the zero-sequence current component after the next averaging period ends. A zero-phase current transformer including a correction calculation circuit for outputting a waveform.
る特許請求の範囲第1項記載の零相変流器。(2) The zero-phase current transformer according to claim 1, wherein the predetermined period is 0.1 seconds or more.
に個別に設けられ且つそれぞれが空隙を有する環状鉄心
と、前記各空隙に配置されたファラデー効果を用いた光
磁界センサと、発光素子及び受光素子と、これら発光素
子及び受光素子を前記各光磁界センサに接続するための
光ファイバとを備えたことを特徴とする特許請求の範囲
第1項又は第2項記載の零相変流器。(3) The optical current transformer includes annular cores each having a gap, each of which is individually provided so that the three-phase distribution line passes through the center, and an optical magnetic field sensor using the Faraday effect placed in each gap. , a light-emitting element, a light-receiving element, and an optical fiber for connecting the light-emitting element and the light-receiving element to each of the optical magnetic field sensors. Phase current transformer.
に個別に設けられた環状鉄心と、これら環状鉄心にそれ
ぞれ巻回された巻線と、これら巻線の各両端間に接続さ
れた抵抗器と、これら抵抗器の各両端間の電圧を計測す
るためのポッケルス効果を用いた光電圧センサと、発光
素子及び受光素子と、これら発光素子及び受光素子を前
記各光電圧センサに接続するための光ファイバとを備え
たことを特徴とする特許請求の範囲第1項又は第2項記
載の零相変流器。(4) An optical current transformer consists of an annular core that is individually installed so that a three-phase distribution line passes through the center, windings wound around each of these annular cores, and a connection between each end of each of these windings. A connected resistor, a photovoltage sensor using the Pockels effect for measuring the voltage across each end of these resistors, a light emitting element and a light receiving element, and the light emitting element and the light receiving element being connected to each of the above photovoltage sensors. 3. The zero-phase current transformer according to claim 1, further comprising an optical fiber for connection to a zero-phase current transformer.
に個別に設けられた環状のファラデー効果を用いた光磁
界センサと、発光素子及び受光素子と、これら発光素子
及び受光素子を前記各光磁界センサに接続するための光
ファイバとを備えたことを特徴とする特許請求の範囲第
1項又は第2項記載の零相変流器。(5) An optical current transformer consists of an annular optical magnetic field sensor using the Faraday effect, which is individually provided so that a three-phase distribution line passes through the center, a light emitting element and a light receiving element, and a light emitting element and a light receiving element. 3. The zero-phase current transformer according to claim 1, further comprising an optical fiber for connecting the optical magnetic field sensor to each of the optical magnetic field sensors.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10474887A JPS63274322A (en) | 1987-04-30 | 1987-04-30 | Zero-phase current transformer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10474887A JPS63274322A (en) | 1987-04-30 | 1987-04-30 | Zero-phase current transformer |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS63274322A true JPS63274322A (en) | 1988-11-11 |
Family
ID=14389114
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP10474887A Pending JPS63274322A (en) | 1987-04-30 | 1987-04-30 | Zero-phase current transformer |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS63274322A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109298230A (en) * | 2018-08-13 | 2019-02-01 | 北京四方继保自动化股份有限公司 | Acquisition device for current transformer |
-
1987
- 1987-04-30 JP JP10474887A patent/JPS63274322A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109298230A (en) * | 2018-08-13 | 2019-02-01 | 北京四方继保自动化股份有限公司 | Acquisition device for current transformer |
CN109298230B (en) * | 2018-08-13 | 2021-04-30 | 北京四方继保自动化股份有限公司 | Acquisition device for current transformer |
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