JPH063389A - Detecting method and device for phase error of current transformer - Google Patents
Detecting method and device for phase error of current transformerInfo
- Publication number
- JPH063389A JPH063389A JP16287392A JP16287392A JPH063389A JP H063389 A JPH063389 A JP H063389A JP 16287392 A JP16287392 A JP 16287392A JP 16287392 A JP16287392 A JP 16287392A JP H063389 A JPH063389 A JP H063389A
- Authority
- JP
- Japan
- Prior art keywords
- current
- transformer
- voltage
- output
- phase
- 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
- Measuring Phase Differences (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】この発明は、電力管理用計器や電
力量計等の試験装置に使用される変流器の位相誤差を検
出する方法およびその装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting a phase error of a current transformer used in a test apparatus such as a power management meter and a watt hour meter.
【0002】[0002]
【従来の技術】従来、変流器(以下CTという)の位相
誤差検出は、一次電流と二次電流を適当な大きさの電圧
に変換し、オシロスコープに入力してそのずれを読みと
ることによって行っていた。また、電力量計の試験とし
て基準器と供試品を比較する方法も行われている。2. Description of the Related Art Conventionally, a phase error of a current transformer (hereinafter referred to as CT) is detected by converting a primary current and a secondary current into a voltage having an appropriate magnitude, inputting the voltage to an oscilloscope, and reading the deviation. Was there. In addition, a method of comparing the standard device and the sample under test is also used as a test of the electricity meter.
【0003】[0003]
【発明が解決しようとする課題】しかしながら、オシロ
スコープで読みとる振幅の大きさに対して位相のずれは
非常に小さいので、精度よく読みとることができないと
いう問題点があった。そこで、この読みとり精度を高め
るために、変換した電圧から矩形波をつくるアンプを通
してオシロスコープに入力させる等の方法も講じられて
いるが、アンプ自体の精度やコストの点で問題があっ
た。However, since the phase shift is very small with respect to the magnitude of the amplitude read by the oscilloscope, there is a problem in that it cannot be read accurately. Therefore, in order to improve the reading accuracy, a method of inputting the rectangular wave from the converted voltage to an oscilloscope through an amplifier is also taken, but there is a problem in accuracy and cost of the amplifier itself.
【0004】一方、電力量計の試験として基準器と供試
品を比較する方法では、入力電力の電流電圧波形を作る
ために高価な波形発生器や電力増幅のアンプを必要とし
ていた。したがって、この発明の目的は、高価な計測器
等を使用せず、より簡単に精度よく位相誤差を検出でき
る変流器位相誤差検出方法およびその装置を提供するこ
とである。On the other hand, in the method of comparing the reference device with the DUT as a test of the watt-hour meter, an expensive waveform generator and an amplifier for power amplification are required to create the current-voltage waveform of the input power. Therefore, an object of the present invention is to provide a current transformer phase error detection method and apparatus that can detect a phase error more easily and accurately without using an expensive measuring instrument or the like.
【0005】[0005]
【課題を解決するための手段】請求項1記載の変流器位
相誤差検出方法は、3相電源のうち2相を変成して60
度の位相差を持つ電流と電圧を取り出し、この電流を一
次電流として基準用変流器と試験用変流器からそれぞれ
二次電流を取り出し、これら各二次電流と前記変成され
た電圧とからそれぞれの有効電力量を測定し、これら有
効電力量を比較することによって試験用変流器の位相誤
差を求めるようにしている。A current transformer phase error detection method according to claim 1, wherein two phases of a three-phase power supply are transformed to 60.
The current and voltage with a phase difference of degrees are taken out, the secondary currents are taken out from the reference current transformer and the test current transformer, respectively, using this current as the primary current, and these secondary currents and the transformed voltage are taken out. The active energy of each is measured, and the phase error of the test current transformer is determined by comparing these active energy.
【0006】請求項2記載の変流器位相誤差検出装置
は、3相電源のうち2相を変成して60度の位相差を持
つ電流と電圧を取り出す電流用変換トランスおよび電圧
用変換トランスと、電流用変換トランスから出力された
電流を一次電流とする試験用変流器から出力された二次
電流と電圧変換用トランスから出力された電圧とを入力
として電力量を積算する第1の電力量計と、電流用変換
トランスから出力された電流を一次電流とする基準用変
流器から出力された二次電流と電圧変換用トランスから
出力された電圧とを入力として電力量を積算する第2の
電力量計とを備えている。According to another aspect of the present invention, there is provided a current transformer phase error detection device comprising a current conversion transformer and a voltage conversion transformer for transforming two phases of a three-phase power source to extract a current and a voltage having a phase difference of 60 degrees. A first electric power for integrating the electric energy with the secondary current output from the test current transformer having the current output from the current conversion transformer as the primary current and the voltage output from the voltage conversion transformer as inputs A quantity meter and a secondary current output from a reference current transformer whose primary current is the current output from the current conversion transformer, and a voltage output from the voltage conversion transformer are input, and the electric energy is integrated. It is equipped with two electric power meters.
【0007】[0007]
【作用】この発明の構成によれば、3相電源の位相のず
れが120度であることを利用し、2相を変成して12
0度の位相差を持つ電圧と電流信号のどちらかの信号の
極性を逆にすることで60度の位相差を持つ電流と電圧
を取り出すことができる。これらを信号入力として試験
用変流器と基準用変流器のそれぞれについて有効電力を
求めれば、位相差60度すなわち力率0.5の電力とし
て求められる。試験用変流器の位相が例えば3度ずれて
いると、力率0.5の電力としては9%程度の誤差とな
る。そこで、このようにして求めた両者の有効電力量を
比較し、これらの誤差から逆算することによって変流器
の位相誤差が検出される。According to the structure of the present invention, by utilizing the fact that the phase difference of the three-phase power source is 120 degrees, the two phases are transformed to 12 degrees.
By reversing the polarity of either the voltage or current signal having a phase difference of 0 degrees, the current and voltage having a phase difference of 60 degrees can be extracted. When the active power is calculated for each of the test current transformer and the reference current transformer using these as signal inputs, the power with a phase difference of 60 degrees, that is, a power factor of 0.5 can be obtained. If the phase of the test current transformer is deviated, for example, by 3 degrees, an error of about 9% is obtained as the power having a power factor of 0.5. Therefore, the phase error of the current transformer is detected by comparing the active power amounts of the two thus obtained and back calculating from these errors.
【0008】[0008]
【実施例】以下、この発明の実施例を図面を参照しなが
ら説明する。図1は、この発明の実施例である変流器位
相誤差検出装置1の構成を示すブロック図で、図におい
て、2は3相電源、3は3相電源2のうち1相を変成し
て電力入力用の電流信号を取り出す電流用変換トラン
ス、4は3相電源2のうち1相を変成して電力入力用の
電圧信号を取り出す電圧用変換トランス、5は試験用変
流器、6は基準用変流器、7は電流用変換トランス3か
ら出力された電流を一次電流として試験用変流器5から
出力された二次電流と電圧変換用トランス4から出力さ
れた電圧とを入力として電力量を積算する第1の電力量
計、8は電流用変換トランス3から出力された電流を一
次電流として基準用変流器6から出力された二次電流と
電圧変換用トランス4から出力された電圧とを入力とし
て電力量を積算する第2の電力量計である。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a current transformer phase error detection apparatus 1 according to an embodiment of the present invention. In the figure, 2 is a three-phase power supply, and 3 is a three-phase power supply 2 with one phase being transformed. A current conversion transformer for taking out a current signal for power input, 4 is a voltage transformation transformer for taking out a voltage signal for power input by transforming one phase of the three-phase power source 2, 5 is a test current transformer, and 6 is The reference current transformer 7 uses the current output from the current conversion transformer 3 as a primary current and the secondary current output from the test current transformer 5 and the voltage output from the voltage conversion transformer 4 as inputs. A first watt-hour meter that integrates the amount of electric power, 8 is a secondary current output from the reference current transformer 6 and an output from the voltage conversion transformer 4 with the current output from the current conversion transformer 3 as the primary current. Second electric energy that integrates the electric energy with the input voltage It is.
【0009】上記した電流用変換トランス3および電圧
用変換トランス4では、3相電源2の位相のずれが12
0度であることを利用し、3相電源2の1つの相から電
流、他の相から電圧を取り出す。図2(a)はその位相
関係を示すが、電流電圧のどちらかの極性を反転して変
成すれば、同図(b)に示すように、60度の位相差を
持った電流と電圧を得ることができる。電源の出力端子
を適当に選定することで、容易に60度の進みあるいは
遅れの位相差を得ることができる。In the current conversion transformer 3 and the voltage conversion transformer 4 described above, the phase shift of the three-phase power source 2 is 12
Utilizing the fact that it is 0 degrees, current is taken out from one phase of the three-phase power supply 2 and voltage is taken out from the other phase. FIG. 2A shows the phase relationship, but if one of the polarities of the current and voltage is inverted and transformed, as shown in FIG. 2B, a current and a voltage with a phase difference of 60 degrees are generated. Obtainable. By properly selecting the output terminal of the power supply, it is possible to easily obtain a phase difference of 60 degrees in advance or delay.
【0010】第1の電力量計7は、電流用変換トランス
3から出力された電流を一次電流として試験用変流器5
から出力された二次電流が入力する電流入力部9と、電
圧変換用トランス4から出力された電圧が入力する電圧
入力部10とを備え、これら電力入力信号は乗算器11
で乗算される。乗算器11の出力はV/F変換器12で
周波数信号に変換され、分周器13を介して積算カウン
タ14で積算され有効電力量が求められる。The first watt-hour meter 7 uses the current output from the current conversion transformer 3 as a primary current and the test current transformer 5
The current input unit 9 into which the secondary current output from the voltage conversion transformer 4 is input, and the voltage input unit 10 into which the voltage output from the voltage conversion transformer 4 is input are provided.
Is multiplied by. The output of the multiplier 11 is converted into a frequency signal by the V / F converter 12, and integrated by the integration counter 14 via the frequency divider 13 to obtain the amount of active power.
【0011】第2の電力量計8も第1の電力量計7と同
様に構成されており、電流用変換トランス3から出力さ
れた電流を一次電流として基準用変流器6から出力され
た二次電流と電圧変換用トランス4から出力された電圧
とを入力として電力量を積算する。これら第1の電力量
計7および第2の電力量計8では、電力入力信号が上記
したように位相差60度すなわち力率0.5(cos6
0°=0.5)の有効電力として求められる。したがっ
て、試験用変流器5の位相が例えば−3度ずれていると
すれば、有効電力は電圧V、電流I、力率cosΦとし
てV・I・cosΦで求められるが、cos60°=
0.5に対してcos57°=0.545となり電力と
しては9%の誤差として現れてくる。逆に電力として1
%の誤差のときはarccos0.505=59.67
となり位相差としては−0.33度のずれがあることが
わかる。The second watt-hour meter 8 is also configured similarly to the first watt-hour meter 7, and the current output from the current conversion transformer 3 is output as the primary current from the reference current transformer 6. The secondary current and the voltage output from the voltage conversion transformer 4 are input, and the electric energy is integrated. In the first watt-hour meter 7 and the second watt-hour meter 8, as described above, the power input signal has a phase difference of 60 degrees, that is, a power factor of 0.5 (cos6).
It is calculated as active power of 0 ° = 0.5). Therefore, if the phase of the test current transformer 5 is deviated by, for example, -3 degrees, the active power is obtained by the voltage V, the current I, and the power factor cosΦ by VI · cosΦ, where cos60 ° =
Cos 57 ° = 0.545 with respect to 0.5, and an error of 9% appears as electric power. On the contrary, as power
When the error is%, arccos 0.505 = 59.67.
It can be seen that there is a shift of -0.33 degrees as the phase difference.
【0012】力率角が0度近傍では変流器出力の位相誤
差による力率角の誤差は電力としては小さい誤差にしか
ならないが、上記したように、力率0.5となる60度
では位相誤差が電力としては大きく扱えるので、このこ
とを利用して3相電源2から力率角60度となる電流電
圧を信号入力としものである。このように第1の電力量
計7と第2の電力量計8によって求めた両者の有効電力
量の誤差を求め、逆算することによって試験用変流器5
の位相のずれを求めることができる。使用する電力量計
の精度がよければ、電力量で精度をみることから時間を
かけて試験するこにより、高精度に位相誤差を検出する
ことができる。When the power factor angle is close to 0 degree, the error of the power factor angle due to the phase error of the current transformer output is only a small error in terms of electric power. Since the phase error can be treated as a large amount of electric power, this is used to input the current voltage from the three-phase power source 2 as a signal input to a power factor angle of 60 degrees. In this way, the error of the active electric energy between the first electric energy meter 7 and the second electric energy meter 8 is obtained, and the error is calculated back to obtain the test current transformer 5.
The phase shift of can be obtained. If the accuracy of the watt-hour meter used is good, it is possible to detect the phase error with high accuracy by checking the accuracy of the watt-hour amount and testing over time.
【0013】[0013]
【発明の効果】この発明の変流器位相誤差検出方法およ
びその装置によれば、変流器の位相誤差検出を、試験用
変流器と基準用変流器に対して2台の電力量計による出
力電力量を比較することにより、有効電力量の誤差から
逆算によって位相ずれを求めるようにしているので、従
来のように位相ずれをオシロスコープで直接読む必要が
なく、使用する計測器や電源に高価な装置を必要とせ
ず、簡単に変流器の位相誤差を検出することができる。According to the current transformer phase error detection method and apparatus of the present invention, the phase error detection of the current transformer is performed by using two electric power amounts for the test current transformer and the reference current transformer. Since the phase shift is calculated by back-calculating from the error of the active power by comparing the output power of the meter, it is not necessary to read the phase shift directly with an oscilloscope as in the conventional method, and the measuring instrument and power supply used. The phase error of the current transformer can be detected easily without requiring an expensive device.
【図1】この発明の実施例である変流器位相誤差検出装
置の構成を示すブロック図である。FIG. 1 is a block diagram showing the configuration of a current transformer phase error detection device that is an embodiment of the present invention.
【図2】(a)は3相電源の出力位相を示す図で、
(b)は実施例において3相電源から変成して得られる
電流電圧信号の位相関係を示す図である。FIG. 2A is a diagram showing an output phase of a three-phase power supply,
(B) is a figure which shows the phase relationship of the current voltage signal obtained by transforming from a 3-phase power supply in an Example.
1 変流器位相誤差検出装置 2 3相電源 3 電流用変換トランス 4 電圧用変換トランス 5 試験用変流器 6 基準用変流器 7 第1の電力量計 8 第2の電力量計 1 Current Transformer Phase Error Detector 2 3 Phase Power Supply 3 Current Conversion Transformer 4 Voltage Conversion Transformer 5 Test Current Transformer 6 Reference Current Transformer 7 First Electricity Meter 8 Second Electricity Meter
Claims (2)
位相差を持つ電流と電圧を取り出し、この電流を一次電
流として基準用変流器と試験用変流器からそれぞれ二次
電流を取り出し、これら各二次電流と前記変成された電
圧とからそれぞれの有効電力量を測定し、これら有効電
力量を比較することによって試験用変流器の位相誤差を
求めることを特徴とする変流器位相誤差検出方法。1. A two-phase three-phase power supply is transformed to extract a current and a voltage having a phase difference of 60 degrees, and this current is used as a primary current for secondary current from a reference current transformer and a test current transformer, respectively. The present invention is characterized in that a current is taken out, each active current amount is measured from each of the secondary currents and the transformed voltage, and the active current amount is compared to obtain the phase error of the test current transformer. Current transformer phase error detection method.
位相差を持つ電流と電圧を取り出す電流用変換トランス
および電圧用変換トランスと、前記電流用変換トランス
から出力された電流を一次電流とする試験用変流器から
出力された二次電流と前記電圧変換用トランスから出力
された電圧とを入力として電力量を積算する第1の電力
量計と、前記電流用変換トランスから出力された電流を
一次電流とする基準用変流器から出力された二次電流と
前記電圧変換用トランスから出力された電圧とを入力と
して電力量を積算する第2の電力量計とを備えたことを
特徴とする変流器位相誤差検出装置。2. A conversion transformer for current and a conversion transformer for voltage for extracting a current and a voltage having a phase difference of 60 degrees by transforming two phases of a three-phase power supply, and a current output from the conversion transformer for current. A first watt-hour meter that integrates the amount of electric power with the secondary current output from the test current transformer as the primary current and the voltage output from the voltage conversion transformer as inputs, and from the current conversion transformer A second watt-hour meter that integrates the amount of electric power with the secondary current output from the reference current transformer that uses the output current as the primary current and the voltage output from the voltage conversion transformer as inputs A current transformer phase error detection device characterized by the above.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16287392A JPH063389A (en) | 1992-06-22 | 1992-06-22 | Detecting method and device for phase error of current transformer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16287392A JPH063389A (en) | 1992-06-22 | 1992-06-22 | Detecting method and device for phase error of current transformer |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH063389A true JPH063389A (en) | 1994-01-11 |
Family
ID=15762894
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP16287392A Pending JPH063389A (en) | 1992-06-22 | 1992-06-22 | Detecting method and device for phase error of current transformer |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH063389A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010243372A (en) * | 2009-04-07 | 2010-10-28 | Tohoku Keiki Kogyo Kk | Watt-hour meter difference measurement system |
CN101930064A (en) * | 2009-06-23 | 2010-12-29 | 华东电力试验研究院有限公司 | Delay measuring method of merging unit and system thereof |
CN103235183A (en) * | 2013-04-17 | 2013-08-07 | 广东新昇电业科技股份有限公司 | Measurement and calculation method for three-phase transformer phases |
CN104133189A (en) * | 2014-07-15 | 2014-11-05 | 广东电网公司中山供电局 | Method and device for detecting electric quantity return and supplement error at voltage loss of one phase of three-phase four-wire electric energy meter |
CN104215928A (en) * | 2014-09-11 | 2014-12-17 | 国家电网公司 | Analytical model method for current conversion ratio and phase difference of open-type current transformer |
CN104267368A (en) * | 2014-10-14 | 2015-01-07 | 国家电网公司 | Fault monitoring method for secondary circuit of metering current transformer |
CN104678344A (en) * | 2015-03-04 | 2015-06-03 | 太原市优特奥科电子科技有限公司 | Novel method and instrument for testing secondary voltage drop of voltage transformer |
-
1992
- 1992-06-22 JP JP16287392A patent/JPH063389A/en active Pending
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010243372A (en) * | 2009-04-07 | 2010-10-28 | Tohoku Keiki Kogyo Kk | Watt-hour meter difference measurement system |
CN101930064A (en) * | 2009-06-23 | 2010-12-29 | 华东电力试验研究院有限公司 | Delay measuring method of merging unit and system thereof |
CN103235183A (en) * | 2013-04-17 | 2013-08-07 | 广东新昇电业科技股份有限公司 | Measurement and calculation method for three-phase transformer phases |
CN104133189A (en) * | 2014-07-15 | 2014-11-05 | 广东电网公司中山供电局 | Method and device for detecting electric quantity return and supplement error at voltage loss of one phase of three-phase four-wire electric energy meter |
CN104133189B (en) * | 2014-07-15 | 2017-01-25 | 广东电网公司中山供电局 | Method and device for detecting electric quantity return and supplement error at voltage loss of one phase of three-phase four-wire electric energy meter |
CN104215928A (en) * | 2014-09-11 | 2014-12-17 | 国家电网公司 | Analytical model method for current conversion ratio and phase difference of open-type current transformer |
CN104215928B (en) * | 2014-09-11 | 2017-02-15 | 国家电网公司 | Analytical model method for current conversion ratio and phase difference of open-type current transformer |
CN104267368A (en) * | 2014-10-14 | 2015-01-07 | 国家电网公司 | Fault monitoring method for secondary circuit of metering current transformer |
CN104678344A (en) * | 2015-03-04 | 2015-06-03 | 太原市优特奥科电子科技有限公司 | Novel method and instrument for testing secondary voltage drop of voltage transformer |
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