JP2012135088A - Saturation detector of instrument current transformer - Google Patents

Saturation detector of instrument current transformer Download PDF

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JP2012135088A
JP2012135088A JP2010283369A JP2010283369A JP2012135088A JP 2012135088 A JP2012135088 A JP 2012135088A JP 2010283369 A JP2010283369 A JP 2010283369A JP 2010283369 A JP2010283369 A JP 2010283369A JP 2012135088 A JP2012135088 A JP 2012135088A
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current transformer
instrument
instrument current
transformer
saturation
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Minoru Saeki
稔 佐伯
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Abstract

PROBLEM TO BE SOLVED: To provide a saturation detector determining whether an instrument current transformer is saturated or not without setting a reference value of a voltage or an excitation current at which the transformer is saturated.SOLUTION: A saturation detector 1 of an instrument current transformer comprises: a second instrument current transformer 3 having a primary side connected to an electric circuit 4 which has a saturation magnetic flux level smaller than that of a first instrument current transformer 2 having a primary side connected to the electric circuit 4; and determination means for determining whether the first instrument current transformer 2 is saturated or not by comparing a secondary-side output waveform of the first instrument current transformer 2 with a secondary-side output waveform of the second instrument current transformer 3.

Description

この発明は、電気回路に接続する計器用変流器の飽和を、計器用変流器の出力波形を比較して判定する計器用変流器の飽和検出器に関する。   The present invention relates to a saturation detector for an instrument current transformer that determines the saturation of an instrument current transformer connected to an electric circuit by comparing the output waveform of the instrument current transformer.

発電機などのプラントにある誘導機の起動と停止を繰り返すと、励磁電流の過渡現象などにより、電気回路に接続された計器用変流器が飽和する場合がある。
これは、電気回路に過大な電流が流れると、計器用変流器の励磁電流に応じた直流成分の電流が発生して、計器用変流器の鉄心に残留磁束が発生するためである。この残留磁束が発生する磁束レベルを、飽和する磁束レベルと呼ぶ。
計器用変流器が飽和すると、二次側の出力波形が波形歪となり、正しい測定値が出力されなくなる（例えば、非特許文献１を参照）。 When an induction machine in a plant such as a generator is repeatedly started and stopped, an instrument current transformer connected to an electric circuit may be saturated due to a transient phenomenon of excitation current.
This is because if an excessive current flows in the electric circuit, a direct current component corresponding to the excitation current of the instrument current transformer is generated, and a residual magnetic flux is generated in the iron core of the instrument current transformer. The magnetic flux level at which this residual magnetic flux is generated is called the saturation magnetic flux level.
When the current transformer for the instrument is saturated, the output waveform on the secondary side becomes waveform distortion, and a correct measurement value is not output (for example, see Non-Patent Document 1).

計器用変流器の飽和の検出方法としては、計器用変流器の一次側における電圧又は励磁電流が飽和する値か否かを、計器用変流器の一次側に検出器を設けて、検出するものがある（例えば、特許文献１を参照）。   As a method of detecting the saturation of the instrument current transformer, whether the voltage or excitation current on the primary side of the instrument current transformer is a value that saturates, a detector is provided on the primary side of the instrument current transformer, Some are detected (see, for example, Patent Document 1).

特開２００６−１４９０９９号公報（第２−３頁、第１図）JP 2006-149099 A (page 2-3, FIG. 1)

日本電機工業会、「第１２９号計器用変成器適用指針」、日本電機工業会技術資料、昭和５７年２月２５日、第３３頁Japan Electrical Manufacturers 'Association, “No. 129 Instrument Transformer Application Guidelines”, Japan Electrical Manufacturers' Association Technical Document, February 25, 1982, p. 33

従来、計器用変流器の飽和の検出方法は、計器用変流器が飽和する電圧又は励磁電流という基準値を、計器用変流器の一次側で検出するものであった。
しかし、過渡現象によっては、基準値を超えなくても飽和する場合や、基準値を超えても飽和しない場合があり、計器用変流器の飽和を正確に検出できないという問題があった。 Conventionally, a saturation detection method for an instrument current transformer detects a reference value of voltage or excitation current at which the instrument current transformer saturates on the primary side of the instrument current transformer.
However, depending on the transient phenomenon, there is a case where the saturation occurs even if the reference value is not exceeded, or there is a case where the saturation does not occur even if the reference value is exceeded.

この発明は、計器用変流器が飽和する電圧又は励磁電流という基準値を決めずに、計器用変流器の飽和の有無を判定する飽和検出器を得ることを目的とする。   It is an object of the present invention to obtain a saturation detector that determines the presence or absence of saturation of an instrument current transformer without determining a reference value of voltage or excitation current at which the instrument current transformer saturates.

この発明の計器用変流器の飽和検出器は、電気回路に一次側を接続する第１の計器用変流器より飽和する磁束レベルが小さい電気回路に一次側を接続する第２の計器用変流器と、第１の計器用変流器の二次側出力波形と第２の計器用変流器の二次側出力波形とを比較する比較手段と、比較手段の比較結果により第１の計器用変流器の飽和の有無を判定する判定手段と、を備えるものである。   The saturation detector of the current transformer for an instrument according to the present invention is for a second instrument in which the primary side is connected to an electric circuit having a lower magnetic flux saturation than the first instrument current transformer that connects the primary side to the electric circuit. The comparison means for comparing the current transformer, the secondary output waveform of the first instrument current transformer and the secondary output waveform of the second instrument current transformer, and the comparison result of the comparison means Determining means for determining the presence or absence of saturation of the current transformer.

この発明は、電気回路に一次側を接続する第１の計器用変流器より飽和する磁束レベルが小さい電気回路に一次側を接続する第２の計器用変流器と、第１の計器用変流器の二次側出力波形と第２の計器用変流器の二次側出力波形とを比較する比較手段と、比較手段の比較結果により第１の計器用変流器の飽和の有無を判定する判定手段と、を備えるもので、計器用変流器が飽和する電圧又は励磁電流という基準値を決めずに、計器用変流器の飽和の有無を判定する飽和検出器を得ることができる。   The present invention relates to a second instrument current transformer that connects the primary side to an electric circuit that has a lower magnetic flux level than the first instrument current transformer that connects the primary side to the electric circuit, and the first instrument Comparison means for comparing the secondary output waveform of the current transformer with the secondary output waveform of the second instrument current transformer, and whether or not the first instrument current transformer is saturated depending on the comparison result of the comparison means A saturation detector for determining the presence or absence of saturation of a current transformer without determining a reference value of voltage or excitation current at which the current transformer is saturated. Can do.

この発明の実施の形態１における計器用変流器の飽和検出器の回路図である。It is a circuit diagram of the saturation detector of the current transformer for instrument in Embodiment 1 of this invention. この発明の実施の形態における入力波形の波形図（飽和していない場合）である。It is a wave form diagram (when not saturated) of the input waveform in embodiment of this invention. この発明の実施の形態における入力波形の波形図（飽和している場合）である。It is a wave form diagram (when saturated) in embodiment of this invention. この発明の実施の形態２における計器用変流器の飽和検出器の回路図である。It is a circuit diagram of the saturation detector of the current transformer for instrument in Embodiment 2 of this invention. この発明の実施の形態３における計器用変流器の飽和検出器を使った比率差動継電器の回路図である。It is a circuit diagram of the ratio differential relay using the saturation detector of the current transformer for instrument in Embodiment 3 of this invention. この発明の実施の形態３における比率差動継電器の論理回路のブロック図である。It is a block diagram of the logic circuit of the ratio differential relay in Embodiment 3 of this invention.

実施の形態１．
この発明の実施の形態１は、飽和する磁束レベルが違う２台の計器用変流器を同一の電気回路に接続し、２台の計器用変流器の二次側出力波形を比較して、計器用変流器の飽和を検出するものである。
図１は、この発明の実施の形態１における計器用変流器の飽和検出器の回路図である。図２は、この発明の実施の形態における入力波形の波形図（飽和していない場合）である。図３は、この発明の実施の形態における入力波形の波形図（飽和している場合）である。 Embodiment 1 FIG.
In the first embodiment of the present invention, two instrument current transformers having different saturation magnetic flux levels are connected to the same electric circuit, and the secondary output waveforms of the two instrument current transformers are compared. It detects the saturation of the current transformer for the instrument.
1 is a circuit diagram of a saturation detector of a current transformer for instrument according to Embodiment 1 of the present invention. FIG. 2 is a waveform diagram (when not saturated) of the input waveform according to the embodiment of the present invention. FIG. 3 is a waveform diagram (when saturated) of the input waveform in the embodiment of the present invention.

この発明の実施の形態１における計器用変流器の飽和検出器の構成について、図１をもとに説明する。
変圧器７に繋がる電気回路４に流れる電流の大きさを、第１の計器用変流器２及び第２の計器用変流器３の一次側を電気回路４に接続して、計測する。
第２の計器用変流器３は、第１の計器用変流器２より過電流定数の小さい、飽和する磁束レベルの小さいものを使用する。
計器用変流器の飽和検出器１における比較演算器５は、第１の計器用変流器２の二次側出力波形と第２の計器用変流器３の二次側出力波形とを入力し、２つの出力波形を比較して、比較結果により第１の計器用変流器２の飽和の有無を判定する。
計器用変流器の飽和検出器１の出力結果Ａは、警報装置８に出力されると共に、第１の計器用変流器２の二次側出力Ｂに接続する保護装置９に出力される。この保護装置９には、過電流リレー、比率差動継電器などがあり、変圧器７の保護のために電気回路４を遮断する信号を出力する。 The structure of the saturation detector of the current transformer for instrument in Embodiment 1 of this invention is demonstrated based on FIG.
The magnitude of the current flowing in the electric circuit 4 connected to the transformer 7 is measured by connecting the primary side of the first instrument current transformer 2 and the second instrument current transformer 3 to the electric circuit 4.
As the second instrument current transformer 3, the one having a smaller overcurrent constant and a lower saturation magnetic flux level than the first instrument current transformer 2 is used.
The comparison arithmetic unit 5 in the saturation detector 1 of the instrument current transformer has the secondary output waveform of the first instrument current transformer 2 and the secondary output waveform of the second instrument current transformer 3. Input, compare the two output waveforms, and determine whether the first current transformer 2 is saturated based on the comparison result.
The output result A of the saturation detector 1 of the instrument current transformer is output to the alarm device 8 and also to the protection device 9 connected to the secondary output B of the first instrument current transformer 2. . The protection device 9 includes an overcurrent relay, a ratio differential relay, and the like, and outputs a signal for cutting off the electric circuit 4 for protection of the transformer 7.

この発明の実施の形態１における計器用変流器の飽和検出器の動作について、図１をもとに説明する。
計器用変流器３が飽和していない場合、図２のように、第１の計器用変流器２の二次側出力波形（ａ）と第２の計器用変流器３の二次側出力波形（ｂ）とは、同じ波形となる。
比較演算器５は、夫々の出力波形に対する電流の瞬時値を何点か比較して、全点で電流の瞬時値が同じならば、「同一波形」と判断して「正常」の信号Ａを出力する。
出力波形を比較する方法は、例えば、図２において、時間ｔ１及びｔ２における出力波形の瞬時値を比較して、時間ｔ１及びｔ２で出力波形（ａ）と出力波形（ｂ）との瞬時値が一致すれば、「同一波形」と判断する。 The operation of the saturation detector of the current transformer for instrument according to Embodiment 1 of the present invention will be described with reference to FIG.
When the current transformer 3 is not saturated, as shown in FIG. 2, the secondary output waveform (a) of the first current transformer 2 and the secondary of the second current transformer 3 are obtained. The side output waveform (b) is the same waveform.
The comparator 5 compares the instantaneous values of the current with respect to the respective output waveforms, and if the instantaneous values of the current are the same at all points, it is determined as “the same waveform” and the “normal” signal A is determined. Output.
For example, in FIG. 2, the instantaneous values of the output waveforms (a) and (b) are compared at the times t1 and t2 by comparing the instantaneous values of the output waveforms at the times t1 and t2. If they match, it is determined as “same waveform”.

計器用変流器３が飽和している場合、図３のように、第１の計器用変流器２の二次側出力波形（ａ）と第２の計器用変流器３の二次側出力波形（ｂ）とは、第２の計器用変流器３の二次側出力波形（ｂ）が歪んだ形となる。これは、飽和する磁束レベルが小さい第２の計器用変流器３が、第１の計器用変流器２より先に飽和することで、第２の計器用変流器３の二次側出力波形が歪むためである。
比較演算器５は、夫々の出力波形に対する電流の瞬時値を何点か比較して、どこかの点で電流の瞬時値が違うならば、「波形に差異がある」と判断して「飽和中」の信号Ａを出力する。
出力波形を比較する方法は、例えば、図３において、時間ｔ１及びｔ２における出力波形の瞬時値を比較して、時間ｔ１及びｔ２で出力波形（ａ）と出力波形（ｂ）との瞬時値が一致しないので、「波形に差異がある」と判断する。
したがって、２台の計器用変流器の二次側出力波形を比較して、差異を検出することで、計器用変流器の飽和の有無を判定できる。
次に、計器用変流器の飽和検出器１が「飽和中」の信号Ａを出力すると、警報装置８で警報を鳴らすと共に、第１の計器用変流器２の二次側出力Ｂに接続する保護装置９の動作をロックする。 When the current transformer 3 is saturated, as shown in FIG. 3, the secondary output waveform (a) of the first current transformer 2 and the secondary of the second current transformer 3 The side output waveform (b) is a distorted form of the secondary output waveform (b) of the second instrument current transformer 3. This is because the second instrument current transformer 3 having a small saturation magnetic flux level is saturated before the first instrument current transformer 2, and thus the secondary side of the second instrument current transformer 3. This is because the output waveform is distorted.
The comparator 5 compares the instantaneous values of the current for each output waveform. If the instantaneous value of the current is different at some point, the comparator 5 determines that there is a difference in waveform and The “medium” signal A is output.
For example, in FIG. 3, the instantaneous values of the output waveforms (a) and (b) are compared at the times t1 and t2 by comparing the instantaneous values of the output waveforms at the times t1 and t2. Since they do not match, it is determined that “there is a difference in waveform”.
Therefore, by comparing the secondary output waveforms of the two instrument current transformers and detecting the difference, the presence or absence of saturation of the instrument current transformer can be determined.
Next, when the saturation detector 1 of the instrument current transformer outputs a “saturating” signal A, an alarm is sounded by the alarm device 8 and the secondary output B of the first instrument current transformer 2 is output. The operation of the protective device 9 to be connected is locked.

この発明の実施の形態１によれば、電圧又は励磁電流という基準値を決めずに、計器用変流器の飽和の有無を検出できる。
また、２台の計器用変流器の二次側出力波形の瞬時値を比較するだけなので、比較演算器の処理がシンプルになってコストの低減が図れる。 According to the first embodiment of the present invention, it is possible to detect the presence or absence of saturation of a current transformer for an instrument without determining a reference value of voltage or excitation current.
Further, since only the instantaneous values of the secondary output waveforms of the two instrument current transformers are compared, the processing of the comparison arithmetic unit is simplified and the cost can be reduced.

この発明の実施の形態１によれば、計器用変流器が飽和しているとき、警報が鳴ることで、計器用変流器の飽和をすぐに判断できる。
また、計器用変流器が飽和しているとき、保護装置の動作をロックすることで、保護装置の誤動作を防ぐことができ、不要な停電を発生させない。 According to the first embodiment of the present invention, when the current transformer for the instrument is saturated, an alarm is sounded, so that the saturation of the current transformer for the instrument can be immediately determined.
In addition, when the current transformer for the instrument is saturated, locking the operation of the protective device prevents the protective device from malfunctioning, and does not cause an unnecessary power failure.

実施の形態２．
この発明の実施の形態２は、電気回路に一次側を接続する計器用変流器の二次側に、計器用変流器より飽和する磁束レベルの小さい補助変流器の一次側を接続し、計器用変流器の二次側出力波形と補助変流器の二次側出力波形とを比較して、計器用変流器の飽和を検出するものである。
図４は、この発明の実施の形態２における計器用変流器の飽和検出器の回路図である。 Embodiment 2. FIG.
In the second embodiment of the present invention, the primary side of the auxiliary current transformer having a smaller magnetic flux level than the current transformer for the instrument is connected to the secondary side of the current transformer for the instrument that connects the primary side to the electric circuit. The saturation of the current transformer is detected by comparing the secondary output waveform of the current transformer and the secondary output waveform of the auxiliary current transformer.
FIG. 4 is a circuit diagram of a saturation detector of the current transformer for instrument according to Embodiment 2 of the present invention.

この発明の実施の形態２における計器用変流器の飽和検出器の構成について、図４をもとに説明する。
この発明の実施の形態１と同様の構成の説明は、省略する。
変圧器７に繋がる電気回路４に流れる電流の大きさを、計器用変流器２の一次側を電気回路４に接続して、計測する。補助変流器６の一次側は、計器用変流器２の二次側に接続する。
補助変流器６は、計器用変流器２より過電流定数の小さい、飽和する磁束レベルの小さいものを使用する。
計器用変流器の飽和検出器１における比較演算器５は、計器用変流器２の二次側出力波形と補助変流器６の二次側出力波形とを入力し、２つの出力波形を比較して、比較結果により計器用変流器２の飽和の有無を判定する。 The structure of the saturation detector of the current transformer for instrument in Embodiment 2 of this invention is demonstrated based on FIG.
A description of the same configuration as that of Embodiment 1 of the present invention is omitted.
The magnitude of the current flowing in the electric circuit 4 connected to the transformer 7 is measured by connecting the primary side of the current transformer 2 to the electric circuit 4. The primary side of the auxiliary current transformer 6 is connected to the secondary side of the instrument current transformer 2.
The auxiliary current transformer 6 has a smaller overcurrent constant and a smaller saturation magnetic flux level than the instrument current transformer 2.
The comparison calculator 5 in the saturation detector 1 of the instrument current transformer receives the secondary output waveform of the instrument current transformer 2 and the secondary output waveform of the auxiliary current transformer 6 and inputs two output waveforms. And the presence or absence of saturation of the current transformer 2 is determined based on the comparison result.

この発明の実施の形態２における計器用変流器の飽和検出器の動作について、図４をもとに説明する。
補助変流器６が飽和していない場合、図２のように、計器用変流器２の二次側出力波形（ａ）と補助変流器６の二次側出力波形（ｂ）とは、同じ波形となる。
比較演算器５は、夫々の出力波形に対する電流の瞬時値を何点か比較して、全点で電流の瞬時値が同じならば、「同一波形」と判断して「正常」の信号Ａを出力する。
出力波形を比較する方法は、この発明の実施の形態１と同様のため、説明を省略する。 The operation of the saturation detector of the current transformer for instrument according to Embodiment 2 of the present invention will be described with reference to FIG.
When the auxiliary current transformer 6 is not saturated, the secondary output waveform (a) of the instrument current transformer 2 and the secondary output waveform (b) of the auxiliary current transformer 6 are as shown in FIG. The same waveform.
The comparator 5 compares the instantaneous values of the current with respect to the respective output waveforms, and if the instantaneous values of the current are the same at all points, it is determined as “the same waveform” and the “normal” signal A is determined. Output.
Since the method for comparing the output waveforms is the same as that of the first embodiment of the present invention, the description thereof is omitted.

補助変流器６が飽和している場合、図３のように計器用変流器２の二次側出力波形（ａ）と補助変流器６の二次側出力波形（ｂ）とは、補助変流器６の二次側出力波形（ｂ）が歪んだ形となる。これは、飽和する磁束レベルが小さい補助変流器６が、計器用変流器２より先に飽和することで、補助変流器６の二次側出力波形が歪むためである。
比較演算器５は、夫々の出力波形に対する電流の瞬時値を何点か比較して、どこかの点で電流の瞬時値が違うならば、「波形に差異がある」と判断して「飽和中」の信号Ａを出力する。
出力波形を比較する方法は、この発明の実施の形態１と同様のため、説明を省略する。
したがって、計器用変流器２の二次側出力波形と補助変流器６の二次側出力波形とを比較して、差異を検出することで、計器用変流器の飽和の有無を判定できる。 When the auxiliary current transformer 6 is saturated, the secondary output waveform (a) of the instrument current transformer 2 and the secondary output waveform (b) of the auxiliary current transformer 6 as shown in FIG. The secondary output waveform (b) of the auxiliary current transformer 6 is distorted. This is because the secondary side output waveform of the auxiliary current transformer 6 is distorted when the auxiliary current transformer 6 having a small saturated magnetic flux level is saturated before the current transformer 2 for measuring instrument.
The comparator 5 compares the instantaneous values of the current for each output waveform. If the instantaneous value of the current is different at some point, the comparator 5 determines that there is a difference in waveform and The “medium” signal A is output.
Since the method for comparing the output waveforms is the same as that of the first embodiment of the present invention, the description thereof is omitted.
Therefore, by comparing the secondary output waveform of the instrument current transformer 2 and the secondary output waveform of the auxiliary current transformer 6 and detecting the difference, it is determined whether the instrument current transformer is saturated. it can.

この発明の実施の形態２によれば、この発明の実施の形態１と同様に、電圧又は励磁電流という基準値を決めずに、計器用変流器の飽和の有無を検出できる。
また、計器用変流器の二次側に補助変流器の一次側を接続することで、電気回路に新たな機器を接続しないで、計器用変流器の飽和検出器を、容易に設置でき、省スペースとなる。 According to the second embodiment of the present invention, as in the first embodiment of the present invention, the presence / absence of saturation of the current transformer for the instrument can be detected without determining the reference value of voltage or exciting current.
In addition, by connecting the primary side of the auxiliary current transformer to the secondary side of the instrument current transformer, the saturation detector of the instrument current transformer can be easily installed without connecting new equipment to the electrical circuit. This saves space.

実施の形態３．
この発明の実施の形態３は、比率差動継電器の誤動作を防ぐ、この発明の実施の形態２における計器用変流器の飽和検出器の使用方法である。
図５は、この発明の実施の形態３における計器用変流器の飽和検出器を使った比率差動継電器の回路図である。図６は、この発明の実施の形態３における比率差動継電器の論理回路のブロック図である。 Embodiment 3 FIG.
The third embodiment of the present invention is a method of using the saturation detector of the current transformer for instrument according to the second embodiment of the present invention, which prevents malfunction of the ratio differential relay.
FIG. 5 is a circuit diagram of a ratio differential relay using a saturation detector of an instrument current transformer according to Embodiment 3 of the present invention. FIG. 6 is a block diagram of the logic circuit of the ratio differential relay according to Embodiment 3 of the present invention.

この発明の実施の形態３における計器用変流器の飽和検出器を使った比率差動継電器の構成について、図５をもとに説明する。
この発明の実施の形態２と同様の構成の説明は、省略する。
変圧器７の一次側の電気回路に流れる電流の大きさを、計器用変流器２の一次側を変圧器７の一次側の電気回路に接続して、計測する。補助変流器６の一次側は、計器用変流器２の二次側に接続する。
変圧器７の二次側の電気回路に流れる電流の大きさも、変圧器７の一次側の電気回路と同様に、計測する。
比率差動継電器１０は、変圧器７の一次側及び二次側に接続する計器用変流器２の二次側出力（Ｂ１、Ｂ２）と飽和検出器１の判定結果（Ａ１、Ａ２）とを入力し、変圧器７の内部故障を検出して、変圧器７の保護のために電気回路を遮断する信号を出力する。 The configuration of the differential ratio relay using the saturation detector of the instrument current transformer in Embodiment 3 of the present invention will be described with reference to FIG.
The description of the same configuration as that of Embodiment 2 of the present invention is omitted.
The magnitude of the current flowing through the primary circuit of the transformer 7 is measured by connecting the primary side of the current transformer 2 to the primary circuit of the transformer 7. The primary side of the auxiliary current transformer 6 is connected to the secondary side of the instrument current transformer 2.
The magnitude of the current flowing in the electrical circuit on the secondary side of the transformer 7 is also measured in the same manner as the electrical circuit on the primary side of the transformer 7.
The ratio differential relay 10 includes the secondary output (B1, B2) of the current transformer 2 for the instrument connected to the primary side and the secondary side of the transformer 7, and the determination result (A1, A2) of the saturation detector 1. Is detected, an internal failure of the transformer 7 is detected, and a signal for shutting down the electric circuit is output to protect the transformer 7.

この発明の実施の形態３における比率差動継電器の動作について、図５と図６とをもとに説明する。
比率差動継電器１０の比較演算器Ｇは、変圧器７の一次側及び二次側にある計器用変流器２の電流値（Ｂ１、Ｂ２）を入力して、差異を検出すれば「保護動作：１」の信号を出力し、差異を検出しなければ「保護不動作：０」の信号を出力する。
変圧器７の一次側及び二次側にある計器用変流器２が飽和していない場合、変圧器７の一次側及び二次側にある飽和検出器１の検出結果（Ａ１、Ａ２）を入力して、どちらも「正常：０」となるのでＮＡＮＤ回路Ｈの出力信号が「１」となる。次に、ＡＮＤ回路Ｊの出力信号は、前記ＮＡＮＤ回路Ｈの出力信号が「１」なので、前記比較演算器Ｇの判定結果により、「保護動作：１」又は「保護不動作：０」の信号Ｃを出力する。
変圧器７の一次側又は二次側にあるどちらか一方の計器用変流器２が飽和している場合、変圧器７の一次側及び二次側にある飽和検出器１の検出結果（Ａ１、Ａ２）を入力して、一方が「飽和中：１」で他方が「正常：０」となるのでＮＡＮＤ回路Ｈの出力信号が「１」となる。次に、ＡＮＤ回路Ｊの出力信号は、前記ＮＡＮＤ回路Ｈの出力信号が「１」なので、前記比較演算器Ｇの出力信号により、「保護動作：１」又は「保護不動作：０」の信号Ｃを出力する。 The operation of the proportional differential relay according to Embodiment 3 of the present invention will be described with reference to FIGS.
The comparison arithmetic unit G of the ratio differential relay 10 inputs the current values (B1, B2) of the current transformers 2 on the primary side and the secondary side of the transformer 7 and detects a difference, thereby “protecting”. An operation: 1 signal is output, and if no difference is detected, a “protection non-operation: 0” signal is output.
If the current transformer 2 on the primary side and the secondary side of the transformer 7 is not saturated, the detection results (A1, A2) of the saturation detector 1 on the primary side and the secondary side of the transformer 7 Since both are “normal: 0”, the output signal of the NAND circuit H is “1”. Next, since the output signal of the NAND circuit H is “1”, the output signal of the AND circuit J is a signal of “protection operation: 1” or “protection non-operation: 0” depending on the determination result of the comparison arithmetic unit G. C is output.
When one of the current transformers 2 on the primary side or the secondary side of the transformer 7 is saturated, the detection result (A1) of the saturation detector 1 on the primary side and the secondary side of the transformer 7 , A2), one is “saturating: 1” and the other is “normal: 0”, so the output signal of the NAND circuit H becomes “1”. Next, since the output signal of the NAND circuit H is “1”, the output signal of the AND circuit J is a signal of “protection operation: 1” or “protection non-operation: 0” depending on the output signal of the comparator G. C is output.

変圧器７の一次側及び二次側にある計器用変流器２が飽和している場合、変圧器７の一次側及び二次側にある飽和検出器１の検出結果（Ａ１、Ａ２）を入力して、どちらも「飽和中：１」となるのでＮＡＮＤ回路Ｈの出力信号が「０」となる。次に、ＡＮＤ回路Ｊの出力信号は、前記ＮＡＮＤ回路Ｈの出力信号が「０」なので、前記比較演算器Ｇの出力信号に関係なく、「保護不動作：０」の信号Ｃを出力する。
したがって、変圧器７の一次側及び二次側にある計器用変流器２の飽和を検出できれば、比率差動継電器１０が「保護不動作：０」の信号Ｃを出力するので、計器用変流器２の飽和による誤動作を防ぐことができる。 When the current transformer 2 on the primary side and the secondary side of the transformer 7 is saturated, the detection results (A1, A2) of the saturation detector 1 on the primary side and the secondary side of the transformer 7 are obtained. Since both are “saturated: 1”, the output signal of the NAND circuit H becomes “0”. Next, since the output signal of the NAND circuit H is “0”, the output signal of the AND circuit J outputs the signal C of “protection non-operation: 0” regardless of the output signal of the comparator G.
Therefore, if the saturation of the current transformer 2 on the primary side and the secondary side of the transformer 7 can be detected, the ratio differential relay 10 outputs the signal C of “protection failure: 0”. A malfunction due to saturation of the flow device 2 can be prevented.

なお、計器用変流器の飽和検出器を使って比率差動継電器の誤動作を防ぐ使用方法は、この発明の実施の形態３に限定されず、変圧器以外の機器を保護する比率差動継電器でも適用可能であることは言うまでもない。   In addition, the usage method which prevents the malfunction of a ratio differential relay using the saturation detector of an instrumental current transformer is not limited to Embodiment 3 of this invention, The ratio differential relay which protects apparatuses other than a transformer But it goes without saying that it is applicable.

この発明の実施の形態３によれば、変圧器の一次側及び二次側にある計器用変流器が、どちらも飽和しているとき、比率差動継電器が誤動作することを防ぐことができ、不要な停電を発生させない。   According to Embodiment 3 of the present invention, it is possible to prevent the ratio differential relay from malfunctioning when both the current transformers for the instrument on the primary side and the secondary side of the transformer are saturated. Do not cause unnecessary power outages.

１...計器用変流器の飽和検出器、 ２...第１の計器用変流器、
３...第２の計器用変流器、 ４...電気回路、
５...比較演算器、 ６...補助変流器、
７...変圧器、 ８...警報装置、
９...保護装置、 １０...比率差動継電器 1 ... Saturation detector for instrument current transformer, 2 ... First instrument current transformer,
3 ... second instrument current transformer, 4 ... electric circuit,
5 ... Comparison calculator, 6 ... Auxiliary current transformer,
7 ... transformer, 8 ... alarm device,
9 ... Protection device, 10 ... Ratio differential relay

Claims (2)

電気回路に一次側を接続する第１の計器用変流器より飽和する磁束レベルが小さい前記電気回路に一次側を接続する第２の計器用変流器と、
前記第１の計器用変流器の二次側出力波形と前記第２の計器用変流器の二次側出力波形とを比較する比較手段と、
前記比較手段の比較結果により前記第１の計器用変流器の飽和の有無を判定する判定手段と、を備える計器用変流器の飽和検出器。 A second instrumental current transformer connecting the primary side to the electrical circuit having a lower magnetic flux level than the first instrument current transformer connecting the primary side to the electrical circuit;
Comparison means for comparing the secondary output waveform of the first instrument current transformer and the secondary output waveform of the second instrument current transformer;
A saturation detector for an instrument current transformer, comprising: determination means for determining whether or not the first instrument current transformer is saturated based on a comparison result of the comparison means. 電気回路に一次側を接続する第１の計器用変流器より飽和する磁束レベルの小さい前記第１の計器用変流器の二次側に一次側を接続する第３の計器用変流器と、
前記第１の計器用変流器の二次側出力波形と前記第３の計器用変流器の二次側出力波形とを比較する比較手段と、
前記比較手段の比較結果により前記第１の計器用変流器の飽和の有無を判定する判定手段と、を備える計器用変流器の飽和検出器。 A third instrument current transformer having a primary side connected to a secondary side of the first instrument current transformer having a lower magnetic flux level than a first instrument current transformer connected to the electric circuit. When,
Comparison means for comparing the secondary output waveform of the first instrument current transformer and the secondary output waveform of the third instrument current transformer;
A saturation detector for an instrument current transformer, comprising: determination means for determining whether or not the first instrument current transformer is saturated based on a comparison result of the comparison means.
JP2010283369A 2010-12-20 2010-12-20 Saturation detector of instrument current transformer Pending JP2012135088A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112564041A (en) * 2020-11-30 2021-03-26 北京陆合电力科技有限公司 Secondary open circuit protection system of current transformer

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59117419A (en) * 1982-12-22 1984-07-06 株式会社東芝 Protecting relaying device
JP2005341770A (en) * 2004-05-31 2005-12-08 Hitachi Ltd Protective relay system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59117419A (en) * 1982-12-22 1984-07-06 株式会社東芝 Protecting relaying device
JP2005341770A (en) * 2004-05-31 2005-12-08 Hitachi Ltd Protective relay system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112564041A (en) * 2020-11-30 2021-03-26 北京陆合电力科技有限公司 Secondary open circuit protection system of current transformer
CN112564041B (en) * 2020-11-30 2023-05-12 北京陆合电力科技有限公司 Secondary open circuit protection system of current transformer

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