CN101059559A - On-line calibration and checking method for current inductor transformation ratio and angle difference - Google Patents
On-line calibration and checking method for current inductor transformation ratio and angle difference Download PDFInfo
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- CN101059559A CN101059559A CN 200610066658 CN200610066658A CN101059559A CN 101059559 A CN101059559 A CN 101059559A CN 200610066658 CN200610066658 CN 200610066658 CN 200610066658 A CN200610066658 A CN 200610066658A CN 101059559 A CN101059559 A CN 101059559A
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Abstract
The invention relates to a high-accuracy measurement technical field of current amplitude and phase, in particular to an online mark and check method for the transformation ratio and angle difference of current transformer CT, and a relative system, wherein lg(t) is the sensitive output of the current transformer with linearly mixed lx(t) and lx(t), therefore, Ig(t)=1Ix(t)+a2IS(t), while lx(t) is the object current, ls(t) is the current signal generated on the measurer, a1 and a2 are the sensitive factors of lx(t) and ls(t) on the output signal lg(t) of the current transformer, then the invention uses independent element analysis method to separate signal ls(t) from signal lg(t), to obtainthe evaluated signal ls'(t) of ls(t), and via the mixed factors a1 and a2 to obtain the transformation ratio and angle difference or the like of current transformer in real condition. Via comparing ls'(t) and ls(t), the invention can easily and reliably realize online check of current transformer and check the result of the independent element analysis.
Description
Technical field
The present invention relates to high-acruracy survey, the no-load voltage ratio of current transformer and on-line proving and the method for calibration and the system of angular difference of the magnitude of current in high-acruracy survey technical field, the especially electric system of the amplitude of the magnitude of current and phase place.
Background technology
In the insulating monitoring of power system device or system failure protection and electronic circuit, automatic control system, all need amplitude, frequency and the phase place of high-precision measurement electric current.Measure the insulation dielectric loss tan δ of power equipment, need development current with high accuracy mutual inductor CT (CurrentTransformer), for monitored electronic equipment or system's operate as normal are not influenced, wish that current transformer is a core-theaded type: when measured electric current passes through the core-theaded type current transformer, hope induces and the proportional variation of the amplitude of the tested electric current of punching at the output terminal of current transformer, and phase differential is zero or the constant output signal of phase differential (angular difference).When considering real work, measured punching electric current changes within the specific limits, when the precision that requires to measure is higher, develop that the current transformer of persevering rated transformation ratio and angular difference is very difficult in the broad measurement range.
The current transformer that is used for various power equipments and electronic surveying, control system now, when lab investigation, current amplitude no-load voltage ratio and angular difference precision often can have good performance, can satisfy Testing requirement, but after a period of time of working usually, performance degradation, bigger variation takes place in amplitude no-load voltage ratio and angular difference (particularly angular difference) characteristic.The current transformer that for example insulate and use in the on-line measurement system, all be that coiling forms as magnetic core with high permeability material, behind the actual on-line operation, because variation, the dash current etc. significantly of on-the-spot strong electromagnetic, environment temperature and humidity to the effect of magnetic material, make the performance of current transformer that significantly drift takes place.On the other hand, electronic circuit system is influenced by electromagnetic interference (EMI), working temperature and humidity, device drift etc. equally in the process to current transformer output signal processing and amplifying during current measurement, thereby changes at the aspects such as phase-shift phase that amplifying signal is introduced.Existing current measuring method, can't effectively demarcate and verification these drifts, especially demarcation and the verification under the on-line operation environment, therefore existing most insulated on-line monitoring product is in actual motion, make as insulation dielectric loss tan δ measures etc., can not obtain high precision, reliable and stable measurement result.
Summary of the invention
The objective of the invention is to, at the current transformer problem that magnitude of current amplitude, phase place high precision stably measured exist in actual motion and the present situation of the present research and development of this technology, but research and development a kind of on-line proving at any time and the no-load voltage ratio of verification current transformer and the method for angular difference.This method utilization is at present at the flourish independent component analysis in fields such as signal Processing, signal separation techniques, can remove temperature, humidity, on-the-spot strong electromagnetic, dash current, the working time performance drift that produces in current transformer and the metering circuit that acts on such as aging, but the no-load voltage ratio of on-line proving and verification current transformer and angular difference, accurately determine to reach the amplifying signal and the phase-shift phase of metering circuit, finally reach the purpose of amplitude, frequency and the phase mass of accurate measurement electric current.
Another object of the present invention provides a kind of monitoring method and insulated on-line monitoring system of insulated on-line monitoring system.
Technical solution of the present invention is:
If I
x(t) be measured electric current, for example it can be the earth leakage current of monitored power equipment; I
s(t) be the current signal that our measuring unit produces, its amplitude, phase place and frequency can change according to actual needs, and they are controlled by measuring system, so I
s(t) can be one and be independent of I
x(t) change, according to measuring the current signal that needs change amplitude, phase place and frequency, are subjected to measuring system control; I
g(t) be output signal at current transformer.
I
g(t) be I
x(t) and I
s(t) therefore linear mixed current transformer induction output have: I
g(t)=a
1I
x(t) a
2I
S(t), a wherein
1, a
2Be I
x(t), I
s(t) respectively to current transformer output signal I
g(t) induction coefficient (mixing constant).By the method for independent component analysis, with signal I
s(t) from signal I
g(t) separate in, obtain I
s(t) estimated signal I
s' (t), from the mixing constant a that calculates
1, a
2Can calculate and obtain no-load voltage ratio and the current transformer characteristic coefficient such as angular difference of current transformer in actual working environment, wherein, I
x(t) be measured electric current, I
s(t) be the current signal that measuring unit produces, with I
s' (t) and I
s(t) compare, can realize the current transformer on-line testing very convenient, reliably, and the correctness of check independent component analysis result of calculation.
Among the present invention, measuring current I
s(t) regard as two quadrature components and, the unknown adds with coefficient and is respectively s1, s2 is with mixed current transformer output signal I
g(t) add respectively these two components can the people for obtaining two mixed signals, to by this two mixed signals and I
g(t) matrix of Zu Chenging carries out independent component analysis (ICA) computing, can obtain three source components: comprise above-mentioned two quadrature components and measured electric current I
x(t), also obtain the mixed coefficient of these three components simultaneously, be respectively s1, s2 and a2.Again these two quadrature components are added according to coefficient s1 in the separating resulting and s2 and obtain I
s(t) estimated signal I
s' (t) and its mixed coefficient a1.
This signal separating method based on independent component analysis is the high precision separation method that has available a kind of comparative maturity now, the basic meaning of independent component analysis is according to adding up independently principle with the hyperchannel observation signal, be decomposed into some isolated components by optimized Algorithm, these components are the estimations to source signal, and observation signal can be rebuild by the linear combination of these isolated components.The basic premise condition of independent component analysis is that source signal is non-Gaussian distribution.Because ICA more meets the actual conditions of signal for the hypothesis of the non-Gaussian distribution of signal, therefore it has bigger application potential in the signal Processing field, and ICA has been successfully applied to fields such as voice signal separation, processing of biomedical signals, recognition of face, separation of images at present.
By the method for independent component analysis, we can be with signal I
s(t) from signal I
g(t) separate in, obtain I
s(t) estimated signal I
s' (t).From the mixing constant a that calculates
1, a
2Can calculate easily and obtain no-load voltage ratio and the current transformer characteristic coefficient such as angular difference of current transformer in actual working environment.Independent component analysis can also obtain tested current signal I simultaneously in result of calculation
x(t) estimated signal value.Because practical function is in the I of current transformer
s(t) be the electric current that measuring unit produces under system's control, so the I that independent component analysis calculates
s' (t), can produce, practical function is in the current signal I of current transformer with system
s(t) compare, so just can realize the current transformer on-line testing very convenient, reliably, and the correctness of check independent component analysis result of calculation.The demarcation of this current transformer ratio and angular difference and method of calibration are suitable for current transformer to on-line operation equally and carry out demarcation and verification under the site environment, and can guarantee to demarcate with check results be high-precision, highly reliable.
When the no-load voltage ratio of the current transformer described in specific implementation the present invention and the on-line proving of angular difference and method of calibration, can utilize CPU computing unit control survey electric current I
s(t) generation makes I
s(t) and I
x(t) jointly by current transformer, obtain mixed current transformer output signal I
g(t), with I
g(t) and I
s(t) send into the passage 1 and the passage 2 of data acquisition system (DAS) simultaneously, send into the CPU computing unit after the digitizing and carry out independent component analysis and Signal Separation, signal and the digitized I after separating
s(t) relatively, finish the no-load voltage ratio and the angular difference of on-line proving and verification current transformer.
Advantage of the present invention:
1. the on-line proving of the no-load voltage ratio of current transformer of the present invention and angular difference and calibration technology not only can be used in laboratory environment, and more crucial is to use in non-lab environment.This site environment that is particularly suitable for, and the technology of carrying out on-line proving and verification in real time can be removed the systematic error that various ectocines are brought.
2. the on-line proving of the no-load voltage ratio of current transformer of the present invention and angular difference and calibration technology can not influence the original work of current transformer.When demarcating and verification when beginning, can adopt analog switch to disconnect the former work of sensor, finish up to demarcation and verification and return original work again.
3. low cost is finished the no-load voltage ratio of current transformer and the on-line proving and the verification of angular difference.The present invention compares with existing correlation technique, almost do not increase the expense of hardware aspect, the improvement of technology is to finish by the improvement of computing method, and the algorithm of Signal Separation is a flexibility and changeability, based on the just existing available a kind of high precision separation method of the signal separating method of independent component analysis.
4. from current transformer output signal I
g(t) can isolate I accurately in
s(t) the estimated signal I of signal
s' (t), can be with I
s' (t) produce, practical function is in the current signal I of current transformer with system
s(t) compare, realize current transformer on-line proving and verification, guaranteed the high precision and the high reliability of final measurement.
5. the current signal I that produces of measuring unit
s(t) obtain easily, its amplitude, phase place and frequency can change according to actual needs, and they are subjected to the accurate control of measuring unit.
Current transformer can be in a wide frequency range guaranteed performance stable, that is to say, according to adding a stimulus signal I artificially
s(t), can in a wide frequency range, demarcate and verification current transformer performance.The no-load voltage ratio of the current transformer that obtains and angular difference can react under the site environment measured electric current I
x(t) no-load voltage ratio and the angular difference by obtaining behind the current transformer.
Description of drawings
For further specifying technology contents of the present invention, below in conjunction with accompanying drawing and case study on implementation to the detailed description of the invention as after, wherein:
Fig. 1: insulated on-line monitoring system structural representation.
Embodiment
As Fig. 1, be insulated on-line monitoring system structural representation of the present invention.The monitoring method of insulated on-line monitoring system, CPU computing unit control survey electric current I
s(t) generation, I
s(t) and I
x(t), obtain mixed electric current I jointly by current transformer
g(t), I
g(t)=a
1I
x(t)+a
2I
S(t), with I
g(t) and I
s(t) send into the passage 1 and the passage 2 of data acquisition system (DAS) simultaneously, send into the CPU computing unit after the digitizing and carry out independent component analysis and Signal Separation, can obtain I
s(t) estimated signal I
s' (t).From the mixing constant a that calculates
1, a
2Can calculate easily and obtain no-load voltage ratio and the current transformer characteristic coefficient such as angular difference of current transformer in actual working environment, accurately determine and the amplifying signal and the phase-shift phase of metering circuit.Independent component analysis can also obtain tested current signal I simultaneously in result of calculation
x(t) estimated signal value.With the I that calculates
s' (t), produce, practical function is in the current signal I of current transformer with system
s(t) compare, finish the no-load voltage ratio and the angular difference of on-line proving and verification current transformer.Can realize the current transformer on-line testing very convenient, reliably, and the correctness of check independent component analysis result of calculation.
A kind of insulated on-line monitoring system is by current transformer, I
s(t) produce circuit, data acquisition system (DAS), CPU computing unit composition, the output of current transformer is connected in the passage 2 of data acquisition system (DAS), I
s(t) output of generation circuit is connected in the passage 1 of data acquisition system (DAS), and the output of data acquisition system (DAS) is connected in the CPU computing unit, and the output of CPU computing unit is connected in I
s(t) produce circuit.
Claims (4)
1. the on-line proving of the no-load voltage ratio of a current transformer and angular difference and method of calibration is characterized in that: feed a current signal I initiatively for current transformer CT
s(t), the current signal I of measuring unit generation
s(t) can be one and be independent of measured electric current I
x(t) change, according to measuring the current signal that needs change amplitude, phase place and frequency, are subjected to measuring system control, I
g(t) be I
x(t) and I
s(t) therefore linear mixed current transformer induction output have: I
g(t)=a
1I
x(t)+a
2I
S(t), a wherein
1, a
2Be I
x(t), I
s(t) respectively to current transformer output signal I
g(t) induction coefficient is by the method for independent component analysis, with signal I
s(t) from signal I
g(t) separate in, obtain I
s(t) estimated signal I
s' (t), from the mixing constant a that calculates
1, a
2Can calculate and obtain no-load voltage ratio and the current transformer characteristic coefficient such as angular difference of current transformer in actual working environment, with I
s' (t) and I
s(t) compare, can realize the current transformer on-line testing very convenient, reliably, and the correctness of check independent component analysis result of calculation.
2. the on-line proving of the no-load voltage ratio of current transformer as claimed in claim 1 and angular difference and method of calibration is characterized in that: based on the signal separating method of independent component analysis is the high precision separation method of existing available a kind of comparative maturity, measuring current I
s(t) regard as two quadrature components and, the unknown adds with coefficient and is respectively s1, s2 is with mixed current transformer output signal I
g(t) add respectively these two components can the people for obtaining two mixed signals, to by this two mixed signals and I
g(t) matrix of Zu Chenging carries out the independent component analysis computing, can obtain three source components: comprise above-mentioned two quadrature components and measured electric current I
x(t), also obtain simultaneously the mixed coefficient of these three components, be respectively s1, s2 and a2 add according to coefficient s1 in the separating resulting and s2 these two quadrature components and obtain I
s(t) estimated signal I
s' (t) and its mixed coefficient a1.
3. the monitoring method of an insulated on-line monitoring system is characterized in that: CPU computing unit control survey electric current I
s(t) generation, I
s(t) and I
x(t) jointly by current transformer, obtain mixed current transformer output signal I
g(t), I
g(t)=a
1I
x(t)+a
2I
S(t), with I
g(t) and I
s(t) send into the passage 1 and the passage 2 of data acquisition system (DAS) simultaneously, send into the CPU computing unit after the digitizing and carry out independent component analysis and Signal Separation, signal and the digitized I after separating
s(t) relatively, finish the no-load voltage ratio and the angular difference of on-line proving and verification current transformer.
4. an insulated on-line monitoring system is characterized in that: by current transformer, I
s(t) produce circuit, data acquisition system (DAS), CPU computing unit composition, the output of current transformer is connected in the passage 2 of data acquisition system (DAS), I
s(t) output of generation circuit is connected in the passage 1 of data acquisition system (DAS), and the output of data acquisition system (DAS) is connected in the CPU computing unit, and the output of CPU computing unit is connected in I
s(t) produce circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100666588A CN100535681C (en) | 2006-04-17 | 2006-04-17 | On-line calibration and checking method for current inductor transformation ratio and angle difference |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100666588A CN100535681C (en) | 2006-04-17 | 2006-04-17 | On-line calibration and checking method for current inductor transformation ratio and angle difference |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101059559A true CN101059559A (en) | 2007-10-24 |
| CN100535681C CN100535681C (en) | 2009-09-02 |
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ID=38865768
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100666588A Expired - Fee Related CN100535681C (en) | 2006-04-17 | 2006-04-17 | On-line calibration and checking method for current inductor transformation ratio and angle difference |
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Cited By (9)
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| CN101576611B (en) * | 2008-05-09 | 2012-03-28 | 中国科学院半导体研究所 | Method for monitoring current sensor angular difference online based on kernel independent component analysis |
| CN102540130A (en) * | 2012-01-10 | 2012-07-04 | 中国科学院半导体研究所 | Signal separating method applied to on-line angular difference monitoring system of current sensor |
| CN101299062B (en) * | 2008-07-01 | 2012-08-22 | 国网武汉高压研究院 | Device for checking zinc oxide lightning arrester block property current tester |
| CN103983843A (en) * | 2014-05-30 | 2014-08-13 | 杭州佳和电气股份有限公司 | Compensation algorithm for measuring active power and electric energy through forceps-shaped mutual inductor |
| CN107179517A (en) * | 2017-04-19 | 2017-09-19 | 广东恒沃动力科技有限公司 | Sensor calibrating method |
| CN108896948A (en) * | 2018-06-20 | 2018-11-27 | 成都理工大学 | A kind of no-load voltage ratio measuring device and measuring method of tandem test potential device |
| CN113539649A (en) * | 2021-07-14 | 2021-10-22 | 烟台东方威思顿电气有限公司 | Open-close type current transformer and deviation online monitoring method thereof |
| CN113555201A (en) * | 2021-07-22 | 2021-10-26 | 烟台东方威思顿电气有限公司 | High-precision open-close type current transformer and data sampling method thereof |
| CN114236454A (en) * | 2021-12-03 | 2022-03-25 | 北京东方计量测试研究所 | Error calibration method and device of broadband resistor divider |
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| CN1055160C (en) * | 1995-04-06 | 2000-08-02 | 武汉国测电器公司 | Dielectric loss measuring method and equipment for high-voltage electrical equipment |
| CN2624214Y (en) * | 2003-06-14 | 2004-07-07 | 云南电力集团有限公司科技与信息中心 | On-line monitoring device for dielectric loss and capacitance of portable capacitor device |
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- 2006-04-17 CN CNB2006100666588A patent/CN100535681C/en not_active Expired - Fee Related
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|---|---|---|---|---|
| CN101576611B (en) * | 2008-05-09 | 2012-03-28 | 中国科学院半导体研究所 | Method for monitoring current sensor angular difference online based on kernel independent component analysis |
| CN101299062B (en) * | 2008-07-01 | 2012-08-22 | 国网武汉高压研究院 | Device for checking zinc oxide lightning arrester block property current tester |
| CN102540130A (en) * | 2012-01-10 | 2012-07-04 | 中国科学院半导体研究所 | Signal separating method applied to on-line angular difference monitoring system of current sensor |
| CN103983843A (en) * | 2014-05-30 | 2014-08-13 | 杭州佳和电气股份有限公司 | Compensation algorithm for measuring active power and electric energy through forceps-shaped mutual inductor |
| CN103983843B (en) * | 2014-05-30 | 2016-06-01 | 杭州佳和电气股份有限公司 | Compensation algorithm when application forcipated mutual-inductor measures wattful power and electric energy |
| CN107179517B (en) * | 2017-04-19 | 2021-12-14 | 广东恒沃动力科技有限公司 | Sensor calibration method |
| CN107179517A (en) * | 2017-04-19 | 2017-09-19 | 广东恒沃动力科技有限公司 | Sensor calibrating method |
| CN108896948A (en) * | 2018-06-20 | 2018-11-27 | 成都理工大学 | A kind of no-load voltage ratio measuring device and measuring method of tandem test potential device |
| CN108896948B (en) * | 2018-06-20 | 2023-03-21 | 成都理工大学 | Transformation ratio measuring device and method for cascade test transformation equipment |
| CN113539649A (en) * | 2021-07-14 | 2021-10-22 | 烟台东方威思顿电气有限公司 | Open-close type current transformer and deviation online monitoring method thereof |
| CN113555201A (en) * | 2021-07-22 | 2021-10-26 | 烟台东方威思顿电气有限公司 | High-precision open-close type current transformer and data sampling method thereof |
| CN114236454A (en) * | 2021-12-03 | 2022-03-25 | 北京东方计量测试研究所 | Error calibration method and device of broadband resistor divider |
| CN114236454B (en) * | 2021-12-03 | 2024-05-28 | 北京东方计量测试研究所 | Error calibration method and device for broadband resistor divider |
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