CN103969507B - A kind of electric energy quality harmonic analyzes method - Google Patents
A kind of electric energy quality harmonic analyzes method Download PDFInfo
- Publication number
- CN103969507B CN103969507B CN201410233513.7A CN201410233513A CN103969507B CN 103969507 B CN103969507 B CN 103969507B CN 201410233513 A CN201410233513 A CN 201410233513A CN 103969507 B CN103969507 B CN 103969507B
- Authority
- CN
- China
- Prior art keywords
- harmonic
- frequency
- telecommunication
- signal
- sampling
- 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.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 34
- 238000004458 analytical method Methods 0.000 claims abstract description 50
- 238000005070 sampling Methods 0.000 claims abstract description 33
- 230000010354 integration Effects 0.000 claims description 21
- 238000005516 engineering process Methods 0.000 description 10
- 230000003750 conditioning effect Effects 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000003595 spectral effect Effects 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 241001515806 Stictis Species 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Measurement Of Current Or Voltage (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The invention discloses a kind of electric energy quality harmonic improving realization on the basis of plesiochronous DFT and analyze method.Described harmonic analysis method includes: need to carry out the signal of telecommunication X of frequency analysis, and W+2 sampling number evidence of equal interval sampling in sampling electrical network；Change the position of frequency domain sampling when applying plesiochronous DFT to carry out frequency analysis according to the drift μ of signal frequency, the most described frequency domain sampling position is μ 2 π/N.Calculate the amplitude of each harmonic of described signal of telecommunication XAnd initial phase angleFinally, amplitude P of the higher hamonic wave of described voltage signal V and current signal I is calculated respectivelykWith first-harmonic P1Amplitude percentage ratioAnd phase angle difference
Description
The application is Application No.: 201110322629.4, and invention and created name is " a kind of electric energy quality harmonic analyser
Harmonic analysis method ", filing date: the divisional application of the application for a patent for invention on October 21st, 2011.
Technical field
The present invention relates to the technical field that electric energy quality harmonic is analyzed, a kind of high-precision harmonic analysis method.
Background technology
Frequency analysis technology should in various fields such as electric energy quality monitoring, electronic product production testing, electric appliances monitoring
With extensively, it is by the important technical of power system monitor, quality inspection, monitoring of tools.
In power supply grid, the generation of harmonic phenomena is mainly due to large-capacity power equipment, with electric rectification or converter
And other nonlinear-loads cause.Developing rapidly recently as Power Electronic Technique, many industrial undertakings introduce big
Impact load, asymmetric load and the nonlinear load of amount, they inevitably occur that when accessing electrical network harmonic wave is dirty
Dye phenomenon.Therefore, voltage, the current signal of power supply grid is carried out frequency analysis, can preferably observe electric network pollution situation,
And then provide theoretical foundation for power network compensation and purification.
The most widely used technology of frequency analysis is discrete Fourier transform (DFT) and fast Fourier transform at present
(FFT).Frequency analysis technology that quasi-synchronous sampling technique and DFT technique combine (that is: plesiochronous DFT frequency analysis technology) energy
Enough improving the precision of frequency analysis, its formula is:
,
In formula: k is the number of times (such as first-harmonic k=1,3 subharmonic k=3) of the harmonic wave needing acquisition；Sin and cos is respectively sine
And cosine function；And akAnd bkIt is respectively real part and the imaginary part of k subharmonic；N is iterations；W is determined by integration method, uses
During muiltiple-trapezoid integration method, W=nN；It it is a weight coefficient；, for all weight coefficient sums；F (i) is for dividing
The ith sample value of analysis waveform；N is sampling number in the cycle.
In engineer applied, frequency analysis is always by the sampling of finite point and is difficult to the synchronization of stricti jurise and adopts
Sample.So, when applying plesiochronous DFT to carry out frequency analysis, will exist the long scope leakage caused due to truncation effect and
The short scope leakage caused due to fence effect so that analysis result precision is the highest, the most credible.
Summary of the invention
The technical problem to be solved in the present invention is to provide the harmonic wave of the higher electric energy quality harmonic analyser of a kind of precision and divides
Analysis method, to be efficiently modified the analytical error of plesiochronous DFT frequency analysis technology, it is thus achieved that high-precision frequency analysis result, from
And improve reliability and the effectiveness of condition adjudgement of the electric energy quality monitoring equipment theoretical based on frequency analysis.
For solving above-mentioned technical problem, the invention provides the harmonic analysis method of a kind of electric energy quality harmonic analyser,
Described electric energy quality harmonic analyser includes being sequentially connected: sensor, signal conditioning circuit, data acquisition circuit and CPU are mono-
Unit；Described harmonic analysis method comprises the steps:
(1) described CPU element sampling electrical network needs the signal of telecommunication X of frequency analysis, and W+2 sampled point of equal interval sampling
Data f (i), i=0,1 ..., w+1}(W is determined by selected integration method, and the present invention does not specify a certain integration method,
Conventional integration method has muiltiple-trapezoid integration method W=nN, complexification rectangular integration method W=n (N-1), iterative Simpson integration
Methods W=n (N-1)/2 etc., can select suitable integration method according to the practical situation of present invention application.General with complexification
Trapezoidal integration method effect is more satisfactory)；
(2) CPU element starts to apply plesiochronous DFT formula from the sampled point i=0 of described signal of telecommunication X:
Analyze W+1 data and obtain fundamental informationWith；
Then, CPU element starts to apply plesiochronous DFT formula from the sampled point i=1 of described signal of telecommunication X:
Analyze W+1 data and obtain fundamental information；
Application formulaCalculate the frequency drift of described signal of telecommunication X；
Application formula, draw first-harmonic and the high order of described signal of telecommunication X respectively
Harmonic wave；
(3), CPU element calculates first-harmonic and the amplitude of higher hamonic wave of described signal of telecommunication X respectivelyJust
Phase angle；
(5), CPU element calculates amplitude P of higher hamonic wave of described signal of telecommunication X respectivelykWith first-harmonic P1Amplitude percentage ratioAnd phase angle difference, and output display (typically uses the LCD cell that is connected with this CPU element to show
Show).
Described signal of telecommunication X is generally grid ac voltage signal or electrical network ac current signal.
Plesiochronous DFT frequency analysis can suppress long scope to leak effectively, and the main cause of its spectrum leakage is signal
The short scope leakage that frequency drift causes, and the spectral peak peak value that is mainly characterized by of the short scope leakage that signal frequency drift causes goes out
Existing position is synchronous change along with signal frequency drift, so variable fence frequency domain sample can effectively catch according to signal drift
The position that spectral peak peak value occurs, thus obtain high-precision harmonic information.
Equal interval sampling is cycle T and frequency f(such as power frequency component frequency f of the ideal signal according to carrying out frequency analysis
For 50Hz, the cycle is 20mS), sample within a cycle N point, i.e. sample frequency are fs=Nf, and N >=64.
Described W+2 sampling number of sampling is according to being to select accordingly according to selected integration method, according to multiple
Change trapezoidal integration method, then W=nN；According to complexification rectangular integration method, then W=n (N-1)；According to iterative Simpson integration
Method, then W=n (N-1)/2.Then according to sample frequency fs=Nf, it is thus achieved that sampled point data sequence f (i), i=0,1 ..., w+
1}, n >=3, finally this data sequence is carried out frequency analysis.
An iteration coefficientDetermined by integration method, ideal period sampled point N and iterations n, concrete derivation
See document [Dai Xianzhong. quasi-synchro sampling application in some problem [J]. electrical measurement and instrument, 1988, (2): 2-7.].
For all weight coefficient sums.For imaginary part and the real part of k subharmonic, according toJust
Harmonic amplitude and initial phase angle can be obtained.
The drift of signal frequencyIt is according to sampling number N fixing in neighbouring sample point first-harmonic phase angle difference and ideal period
Relation and obtain, the drift of signal frequencyCan also be used for revising first-harmonic and frequency f of higher hamonic wave1Frequency with higher hamonic wave
Rate fk。
Present invention is mainly applied to, in the analysis software of electric energy quality harmonic analyser, be used for improving frequency analysis
Quality, obtain high-precision first-harmonic and the amplitude of higher hamonic wave, phase angle and frequency.Analyzed signal is sampled by the present invention
And analysis, and analysis result (amplitude, phase angle and frequency etc.) is exported according to the requirement of electric energy quality harmonic analyser.The present invention
Electric energy quality harmonic analyser use harmonic analysis method, for frequency analysis technology based on variable fence thought, have
Techniques below advantage:
(1) high-precision frequency analysis result.The analysis result that frequency analysis technology of the present invention obtains is either
More than amplitude or phase angle error 4 orders of magnitude of raising.
(2) frequency analysis technology of the present invention fundamentally solves the problem that plesiochronous DFT analysis precision is low, and
Without carrying out inverting and the correction of complexity, algorithm is simple.
(3) relative to plesiochronous DFT, frequency analysis technology of the present invention has only to increase a sampled point and just solves
The problem that plesiochronous DFT analytical error is big, it is easy to accomplish.
(4) the application present invention improves existing instrument and equipment, is technically feasible, and need not to increase any hard
Part expense just can make analysis result can improve more than 4 orders of magnitude.
(5) variable fence thought is also applied for carrying out successive ignition rather than the frequency analysis process of an iteration too,
Now have only to that an iteration is resolved into successive ignition and realize the most permissible.An iteration is substantially the same with successive ignition
, simply when calculating, successive ignition carries out decoupled method, and an iteration is that the process of successive ignition is merged into iteration system
NumberIn once calculated, so present disclosure applies equally to successive ignition process.
(6) present invention applies plesiochronous DFT to carry out the position drift according to signal frequency of frequency analysis time-frequency domain sampling
And change, the most described frequency domain sampling position is μ 2 π/N, wherein:For the drift of signal frequency, during without driftIt is 1.The present invention
Harmonic analysis method thought based on variable fence, realized by 5 analytical procedures.The thought of variable fence: accurate same
The main cause of step DFT analytical error is that the position that the drift of signal frequency causes spectrum peak to occur occurs inclined with ideal position
Difference, if the most incorrect with the analysis result that obtains if being sampled in a frequency domain still according to 2 π/N.Variable fence refers to
It is: the position of frequency domain sampling is not fixing 2 π/N, but changes according to the drift of signal frequency, i.e. frequency sampling position
Being set to μ 2 π/N(μ is the drift of signal frequency).Frequency domain sampling fence changes along with the drift of signal frequency can accurately be estimated
Go out the position that higher hamonic wave peak value occurs, and then obtain high-precision amplitude and phase angle information.
Detailed description of the invention
Electric energy quality harmonic analyser is mainly by sensor, signal conditioning circuit, data acquisition circuit, CPU, LCD cell
And analyze software composition accordingly.Sensor typically uses voltage transformer and current transformer, the high voltage of tested electrical network
Change by a certain percentage with big current signal；Voltage, current signal that sensor is sent here by signal conditioning circuit are transformed to
It is suitable for the voltage signal of data acquisition circuit sampling；By data acquisition circuit, the signal after conditioning is sampled, then led to by CPU
Cross analysis software and complete the analysis to harmonic wave and detection.
The harmonic analysis method of the electric energy quality harmonic analyser of the present invention, comprises the following steps:
First, CPU element sampling electrical network needs the signal of telecommunication X of frequency analysis, and W+2 sampled point of equal interval sampling,
With obtain described signal of telecommunication X discrete series f (k), k=0,1 ..., w+1}.W is by integration method, iterations n and ideal week
In phase, sampling number N together decides on.Equal interval sampling refers to the frequency f(such as work according to the ideal signal carrying out frequency analysis
Frequently signal frequency is 50Hz, and the cycle is 20mS) determine sample frequency fs=Nf, in sample frequency fsEffect under within a cycle
Sampling N point equably.Usually, periodic sampling point N=64 or above just can obtain preferable frequency analysis result, and iteration is secondary
Number n=3-5 just can obtain comparatively ideal frequency analysis result.Integration method has muiltiple-trapezoid integration method W=nN, complexification rectangle long-pending
Divide method W=n (N-1), Simpson's integration method W=n (N-1)/2 etc. multiple, can select according to practical situation.
Secondly, CPU element starts to apply plesiochronous DFT formula from the sampled point i=0 of described signal of telecommunication X:
Analyze W+1 data and obtain fundamental informationWith.Its
In, an iteration coefficientDetermined by integration method, ideal period sampled point N and iterations n, andAdd for all
Weight coefficient sum.
Then, CPU element starts to apply plesiochronous DFT formula from the sampled point i=1 of described signal of telecommunication X:
Analyze W+1 data and obtain fundamental information。
Then, application formulaCalculate the frequency drift of described signal of telecommunication X
Move.Obtain frequency driftAfter, can be according to sample frequency fsCalculate with sampling number N in ideal period and obtain analyzed letter
Number first-harmonic and frequency f of higher hamonic wave.
Then, application formula, calculate the first-harmonic of described signal of telecommunication X respectively
Real part with higher hamonic waveAnd imaginary part；
CPU element and then according to formula:The first-harmonic and the high order that calculate described signal of telecommunication X respectively are humorous
The amplitude of rippleAnd initial phase angle:。
Finally, CPU element calculates amplitude P of higher hamonic wave of described signal of telecommunication X respectivelykWith first-harmonic P1Amplitude percentage
RatioAnd phase angle difference, and output display (typically uses the LCD cell that is connected with this CPU element to show
Show).
Those skilled in the art it should be appreciated that above embodiment be intended merely to illustrate the present invention, and
Being not intended as limitation of the invention, the present invention can be to be changing into more mode, as long as at the connotation model of the present invention
In enclosing, change, the modification of embodiment described above all will be fallen in the range of claims of the present invention.
Claims (1)
1. an electric energy quality harmonic analyzes method, it is characterised in that comprise the following steps:
(1), the CPU element of electric energy quality harmonic analyser sampling electrical network needs the signal of telecommunication X of frequency analysis, and adopt at equal intervals
W+2 sampling number evidence of sample: f (i), i=0,1 ..., w+1}, W are sampled by integration method, iterations n and ideal period
Points N together decides on；Described equal interval sampling is cycle T and frequency f of the ideal signal according to carrying out frequency analysis, one
In the individual cycle, sampling N point, i.e. sample frequency are fs=Nf, and N >=64；
(2), CPU element starts to apply plesiochronous DFT formula from the sampled point i=0 of described signal of telecommunication X:
Analyze W+1 data and obtain fundamental informationWith
Then, CPU element starts to apply plesiochronous DFT formula from the sampled point i=1 of described signal of telecommunication X:
Analyze W+1 data and obtain fundamental information
With
Application formula:
Calculate frequency drift μ of described signal of telecommunication X；Frequency drift μ is according to neighbouring sample point first-harmonic phase angle difference and ideal period
The fixed relationship of interior sampling number N and obtain, frequency drift μ is for revising frequency f of first-harmonic1Frequency f with higher hamonic wavek；
Application formula:Show that first-harmonic and the high order of described signal of telecommunication X are humorous respectively
The real part a of ripplekWith imaginary part bk；
(3), CPU element calculates first-harmonic and the amplitude of higher hamonic wave of described signal of telecommunication X respectivelyJust
Phase angle
(4), CPU element calculates amplitude P of higher hamonic wave of described signal of telecommunication X respectivelykWith first-harmonic P1Amplitude percentage ratioAnd phase angle differenceAnd output display.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410233513.7A CN103969507B (en) | 2011-10-21 | 2011-10-21 | A kind of electric energy quality harmonic analyzes method |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110322629.4A CN102508026B (en) | 2011-10-21 | 2011-10-21 | Harmonic wave analysis method for electric energy quality harmonic wave analyzer |
| CN201410233513.7A CN103969507B (en) | 2011-10-21 | 2011-10-21 | A kind of electric energy quality harmonic analyzes method |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110322629.4A Division CN102508026B (en) | 2011-10-21 | 2011-10-21 | Harmonic wave analysis method for electric energy quality harmonic wave analyzer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103969507A CN103969507A (en) | 2014-08-06 |
| CN103969507B true CN103969507B (en) | 2016-10-19 |
Family
ID=51239250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410233513.7A Active CN103969507B (en) | 2011-10-21 | 2011-10-21 | A kind of electric energy quality harmonic analyzes method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103969507B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109142866B (en) * | 2015-05-19 | 2020-10-09 | 江苏理工学院 | Harmonic phase angle analysis method based on linear correction algorithm |
| CN113358930B (en) * | 2021-08-09 | 2021-10-29 | 南京派格测控科技有限公司 | Harmonic wave test system, device and method based on signal deviation |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101900761A (en) * | 2009-11-05 | 2010-12-01 | 中国航天科技集团公司第五研究院第五一四研究所 | High-accuracy non-integer-period sampled harmonic analysis and measurement method |
| CN102128982A (en) * | 2010-12-23 | 2011-07-20 | 东莞市创锐电子技术有限公司 | Harmonic analysis method based on windowed interpolation FFT (Fast Fourier Transform) base frequency tracking technology |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006079181A1 (en) * | 2005-01-31 | 2006-08-03 | Genesys Design Pty Ltd | Frequency estimation |
| JP2006276006A (en) * | 2005-03-01 | 2006-10-12 | Nagoya Institute Of Technology | Harmonic analysis method in power system |
-
2011
- 2011-10-21 CN CN201410233513.7A patent/CN103969507B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101900761A (en) * | 2009-11-05 | 2010-12-01 | 中国航天科技集团公司第五研究院第五一四研究所 | High-accuracy non-integer-period sampled harmonic analysis and measurement method |
| CN102128982A (en) * | 2010-12-23 | 2011-07-20 | 东莞市创锐电子技术有限公司 | Harmonic analysis method based on windowed interpolation FFT (Fast Fourier Transform) base frequency tracking technology |
Non-Patent Citations (2)
| Title |
|---|
| 用准同步离散Fourier变换实现高准确度谐波分析;李芙英 等;《清华大学学报（自然科学版）》;19991231;第39卷(第5期);第47-50页 * |
| 进一步提高准同步采样谐波分析法准确度的方案;沈国峰 等;《仪器仪表学报》;20011031;第22卷(第5期);第455-457、465页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103969507A (en) | 2014-08-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103439567B (en) | A kind of method of work of MOA current in resistance property on-line monitoring system | |
| CN102508026B (en) | Harmonic wave analysis method for electric energy quality harmonic wave analyzer | |
| CN103454494B (en) | A kind of high-precision harmonic analysis method | |
| CN102435860B (en) | Working method of medium loss current tester | |
| CN103869162B (en) | Dynamic signal phasor measurement method based on time domain quasi-synchronization | |
| CN103439566B (en) | Operating method of MOA resistive current tester with relatively high precision | |
| CN107543962A (en) | The computational methods of leading m-Acetyl chlorophosphonazo spectrum distribution | |
| CN108896944B (en) | Laboratory calibrator of synchronous measuring device and synchronous phasor measuring method thereof | |
| Jin et al. | A novel power harmonic analysis method based on Nuttall-Kaiser combination window double spectrum interpolated FFT algorithm | |
| CN106226590A (en) | A kind of synchronous phase measuring in power system method | |
| CN103543331B (en) | A kind of method calculating electric signal harmonic wave and m-Acetyl chlorophosphonazo | |
| Oliveira et al. | A contribution for the measuring process of harmonics and interharmonics in electrical power systems with photovoltaic sources | |
| CN109030957B (en) | Dielectric loss measuring method | |
| CN103983852B (en) | Harmonic analysis method of power quality harmonic analyzer | |
| CN103969507B (en) | A kind of electric energy quality harmonic analyzes method | |
| CN104849530B (en) | A kind of measuring method of MOA resistive current first harmonics | |
| CN103604989A (en) | Harmonic wave analysis method of power-quality harmonic wave analyzer | |
| CN103592512A (en) | Harmonic analysis method of power quality harmonic analyzer | |
| CN102435816B (en) | Working method of MOA (Metal Oxide Arrester) resistive current tester | |
| CN104849551B (en) | A kind of humorous phase angle analysis method | |
| CN103267896B (en) | The measuring method of initial phase angle of periodic signal | |
| CN110083891A (en) | A kind of calculation method of the plesiochronous linear correction factor of DFT amplitude | |
| Tong et al. | A highly accurate ECT calibration system based on virtual instrument technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20230109 Address after: 411100 Room 0101001, Unit 1, Building D7, Phase I, Jinrong Xiangtan Intelligent Manufacturing Industrial Park, No. 8, Chezhan South Road, Bantang Street, High-tech Zone, Xiangtan City, Hunan Province Patentee after: HUNAN SENNENG ELECTRIC POWER TECHNOLOGY CO.,LTD. Address before: 213001, No. 1801, Wu Cheng Road, bell tower, Changzhou, Jiangsu Patentee before: JIANGSU University OF TECHNOLOGY |