CN109633262A - Three phase harmonic electric energy gauging method, device based on composite window multiline FFT - Google Patents
Three phase harmonic electric energy gauging method, device based on composite window multiline FFT Download PDFInfo
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R22/00—Arrangements for measuring time integral of electric power or current, e.g. electricity meters
- G01R22/06—Arrangements for measuring time integral of electric power or current, e.g. electricity meters by electronic methods
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- G—PHYSICS
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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Abstract
The present invention discloses a kind of three phase harmonic electric energy gauging method, device based on composite window multiline FFT, and this method step includes: voltage in S1. acquisition power grid, current signal and is converted to digital signal output；S2. signal step S1 exported carries out windowing FFT processing using composite window and carries out frequency analysis based on multi-thread spectrum interpolation, and the parameter of fundamental wave, each harmonic is calculated, and calculates fundamental wave and harmonic electric energy according to the parameter of calculated fundamental wave, each harmonic.The present invention is based on composite window multiline FFT to realize the metering of three phase harmonic electric energy detection, can reduce FFT spectrum leakage and fence effect, improve the precision and spectral resolution of dynamic detecting harmonics metering.
Description
Technical field
The present invention relates to three phase harmonic electric energy detection and field of measuring techniques, more particularly to one kind to be based on composite window multiline
Three phase harmonic electric energy gauging method, the device of FFT.
Background technique
Under current smart grid environment, since the impacts such as a large amount of power electronic equipment and the extensive of nonlinear-load are answered
With causing power grid to generate a large amount of harmonic distortions interference, challenge to the accuracy of current electrical energy measurement, therefore accurately realize humorous
Wave detection has great importance to current power industry with electrical energy measurement research.
Following a few class methods are mainly used for the detection of network system harmonic wave and metering at present:
1. the method based on instantaneous reactive power theory, such method can effectively detect electricity in unbalanced source voltage
Net harmonic wave, time delay is good, but influence of its precision vulnerable to higher order filter, and calculation amount is bigger, higher cost.
2, the method for carrying out harmonic detecting based on wavelet transformation, such method can be realized subband measuring and time-domain signal
The extraction of feature, but real-time is poor, and computationally intensive.
3, harmonic detecting method neural network based, such method mainly include building neural network, determine autonomous learn
The three parts for practising algorithm and harmonic detecting neural network based selection sample, have very strong white adaptation and learning ability, but
For the current many places of such method in conceptual phase, realization is complex, is not easy to practical application.
Above-mentioned harmonic detecting metering method realize it is complex, computationally intensive, be particularly unsuitable for embedded system reality
It is existing.
Another harmonic detecting method: windows and interpolated FFT harmonic analysis method, be by power network signal carry out adding window and
Fast Fourier Transform (FFT) carries out frequency analysis and electrical energy measurement using double spectral line interpolation method, i.e., to the maximum near required frequency
It is worth spectral line and time maximum value spectral line carries out interpolation, since crest frequency is typically not on the Frequency point of discrete spectral line, by right
Spectral line near peak value, which carries out difference, can get accurate signal amplitude parameter, it is possible to reduce implementation complexity and calculation amount is small,
It is applicable to Implementation of Embedded System.But since current windows and interpolated FFT harmonic analysis method is usually all based on bispectrum line
Interpolation method is only to carry out interpolation with time maximum value spectral line to the maximum value spectral line near required frequency, and actually compose in peak value
3 near line even more than spectral line occupy greater weight, only with double spectral line interpolation carry out the precision of frequency analysis with
And frequency spectrum resolving power is not still high.
Summary of the invention
The technical problem to be solved in the present invention is that, for technical problem of the existing technology, the present invention provides one
Kind of implementation method is simple, it is at low cost, can be realized the metering of three phase dynamic harmonic electric energy, and FFT spectrum leakage and side lobe performance are good
And the high three phase harmonic electrical energy measurement based on composite window multiline FFT of dynamic detecting harmonics measuring accuracy, spectral resolution
Method, apparatus.
In order to solve the above technical problems, technical solution proposed by the present invention are as follows:
A kind of three phase harmonic electric energy gauging method based on composite window multiline FFT, step include:
S1. the voltage in power grid, current signal are acquired and is converted to digital signal output；
S2. signal step S1 exported is carried out windowing FFT processing using composite window and is carried out based on multi-thread spectrum interpolation humorous
The parameter of fundamental wave, each harmonic is calculated in wave analysis, according to the parameter of calculated fundamental wave, each harmonic calculate fundamental wave and
Harmonic electric energy.
As a further improvement of that present invention, carrying out frequency analysis based on multi-thread spectrum interpolation in the step S2 is to add to described
More spectral lines in the discrete spectrum that window FFT is handled near required frequency carry out interpolation, and building obtains fundamental wave, each harmonic
The amplitude of parameter, frequency amendment type, the fundamental wave, each harmonic is calculated using the amendment type that building obtains
Amplitude, the frequency of parameter.
As a further improvement of that present invention, specifically used three spectral line interpolations that are based on carry out frequency analysis, are inserted based on three spectral lines
Value constructs the step of amendment type are as follows:
S21. taking the left and right spectral line of peak value spectral line and the peak value spectral line is three spectral line, is composed according to the peak value
Difference between the amplitude of the left and right spectral line of line and contextual definition the parameter γ, Yi Jigen between the amplitude of the peak value spectral line
According to the difference defined parameters ε between the position of the peak value spectral line and the position of true peak spectral line；
S22. the multinomial G (ε) using the corresponding amplitude of three spectral lines and about the parameter ε constructs flickering packet
The amendment type of the amplitude of network, frequency；
S23. it carries out curve fitting to the amendment type, determination obtains the amendment type and the multinomial G of the parameter ε
(ε's) is approximant；
S24. the amendment type, described multinomial of the parameter ε is used in the amplitude of the flicker envelope, the amendment type of frequency
Formula G's (ε) is approximant, finally obtains the amplitude of the parameter of fundamental wave and each harmonic, the amendment type of frequency.
As a further improvement of that present invention, specifically used Blackman-Nuttall window w (n) carries out windowing process, described
In step S21, if peak value spectral line is kthcItem and respective frequencies are kcΔ f, the left side spectral line of the peak value spectral line are kc-1, the right
Adjacent spectral line is kc+1, true peak spectral line is kiAnd respective frequencies are fi, wherein correspond to fundamental wave as i=0, work as i=1,2,
Correspond to each harmonic when 3 ..., the corresponding amplitude of above-mentioned three spectral lines is respectively xc=| Y (kcΔ f) |, xc-1=| Y (kc-1Δ
F) |, xc+1=| Y (kc+1Δf)|；
Defined parameters γ are as follows:
And defined parameters ε=ki-kc, parameter γ is obtained according to the parameter ε of definition and is met:
Wherein WBNFor the discrete spectrum for using Blackman-Nuttall window w (n)；
The amplitude m of the flicker envelope constructed in the step S22iAmendment type are as follows:
The frequency f of the flicker envelopeiAmendment type are as follows:
fi=(kc+ε)Δf。
As a further improvement of that present invention, the amendment type, described more of the obtained parameter ε is determined in the step S23
Approximant being respectively as follows: of item formula G (ε)
The γ -0.08172260 of ε=0.92240086 γ3+0.01577433γ5-0.00331346γ7
G (ε)=1.64427532+0.45294290 ε2+0.06655509ε4+0.00725154ε6
The amplitude m of the parameter of the fundamental wave obtained in the step S24 and each harmonici, frequency fiAmendment type point
Not are as follows:
mi=(2xC+xC-1+xc+1)N-1·(1.64427532+0.45294290ε2+0.06655509ε4+0.00725154
ε6)
fi=(kc+0.92240086γ-0.08172260γ3+0.01577433γ5-0.00331346γ7)Δf。
It as a further improvement of that present invention, further include harmonic electric energy metering error aligning step after the step S2, comprising:
Respectively when power factor is designated value, the wattful power messurement value and use standard harmonic electricity that the step S2 is obtained are obtained
The active power standard value that energy table measurement obtains carries out angular difference correction, fundamental wave angular difference is obtained, according to the obtained fundamental wave angular difference
Calculate the step S2 according to calculated fundamental wave, harmonic wave with obtained using standard harmonic electric energy meter measurement fundamental wave, harmonic wave it
Between active power error, harmonic voltage measurement error, appointing in harmonic current measurement error and harmonic phase measurement error
Anticipate one or more, with determine the step S2 metric results whether meet demand.
As a further improvement of that present invention, the specific steps of the harmonic electric energy metering error correction are as follows:
The measured value of fundamental voltage and fundamental current that step S2 is obtained is respectively U1′、I1', use standard harmonic electric energy meter
Obtained standard value is respectively U1、I1, the phase difference between the measured value and the standard value is θ1, fundamental wave angular difference is φ1,
The standard value P of fundamental active power1With measured value P1' be respectively as follows:
P1=U1I1cosθ1
P1'=U1′I1′cos(θ1+φ1)
=U1I1cos(θ1+φ1)
According to the standard value P of the active power1With measured value P1' obtain fundamental active error are as follows:
Choosing power factor is 1.0 to be tested with 0.5L two o'clock, when power factor is 1.0 by comparing measured value with
Corresponding standard scale indicating value is completed than difference correction, when power factor is 0.5L according to θ1=π/3 and the fundamental active miss
Difference obtains fundamental wave angular difference φ1:
Wherein, err0.5LFor fundamental wave active power factor 0.5L when error amount.
As a further improvement of that present invention, Newton interpolation side is specifically used in the harmonic electric energy metering error aligning step
Method carries out angular difference correction, to carry out signal reconstruction to discrete sample sequence, re-execute the steps S2 to the signal reconstructed
Multi-thread spectrum interpolation progress frequency analysis is handled and be based on to re-start windowing FFT, obtains final fundamental wave and harmonic electric energy meter
Measure result.
As a further improvement of that present invention, described the step of angle correct is carried out using Newton interpolation method are as follows:
Actual sample value y (n), (n-1)th point of the actual sample value y (n-1) for obtaining nth point, according to nth point and (n-1)th
Theoretical sampled value y is calculated in the actual sample value of point:
It enables
Wherein M is correction coefficient, err0.5LError amount when for fundamental active power factor 0.5L.
A kind of three phase harmonic electric energy metering device based on composite window multiline FFT, comprising:
Data acquisition unit, for acquiring the voltage in power grid, current signal and being converted to digital signal output；
Frequency analysis computing unit, the signal for exporting the data acquisition unit carry out adding window using composite window
FFT, which is handled and is based on multi-thread spectrum interpolation, carries out frequency analysis, the parameter of fundamental wave, each harmonic is calculated, according to calculated
The parameter calculating fundamental wave and harmonic electric energy of fundamental wave, each harmonic.
Compared with the prior art, the advantages of the present invention are as follows:
1, the present invention carries out windows and interpolated FFT by using composite window for the detection of power grid dynamic harmonic and electrical energy measurement,
The leakage of dynamic harmonic FFT spectrum and side lobe effect can be reduced, improves the leakage of dynamic harmonic FFT spectrum and side lobe performance, simultaneously
Traditional spectral line interpolation is improved, frequency analysis is carried out using multi-thread spectrum interpolation, the big spectral line of more accountings can be obtained, from
And more abundant, accurately characterization power network signal fundamental wave and harmonic wave characteristic, effectively improve the precision of three phase harmonic dynamic detection
And frequency spectrum resolving power.
2, the present invention carries out interpolation analysis by three spectral lines for taking the left and right spectral line of peak value spectral line and peak value spectral line to constitute
It calculates, the amendment type of the amplitude of flicker envelope, frequency is constructed by amplitude, the frequency according to three spectral lines, curve is used in combination
The mode of fitting obtains the wherein amendment type of parameter, polynomial approximant, to finally obtain fundamental wave and each harmonic
It is humorous to effectively improve nearby can to account for heavy 3 spectral line interpolations based on peak value spectral line for the amendment type of the amplitude of parameter, frequency
Wave analysis precision, while reducing computation complexity.
3, the present invention can construct further by combining Blackman-Nuttall window and three spectral line interpolation methods
To the fundamental wave of measured signal and amplitude, the phase and frequency amendment type of harmonic wave, so as to accurately calculate the base of power network signal
The amplitude of wave and each harmonic component, phase and frequency further increase the precision of harmonic electric energy detection.
4, the present invention be based further on single order Newton Interpolation Algorithm realize angular difference correction, can further improve correction efficiency and
Precision, and practical engineering application can be convenient for, while signal weight can be carried out to discrete sample sequence by Newton Interpolation Algorithm
Structure carries out windows and interpolated FFT calculating using the discrete sampling sequence of points of reconstruct again, can further improve the precision of measurement.
Detailed description of the invention
Fig. 1 is the implementation process signal of three phase harmonic electric energy gauging method of the present embodiment based on composite window multiline FFT
Figure.
Fig. 2 is the schematic illustration of the newton single-point Newton interpolation method used in the present embodiment.
Fig. 3 is the specific implementation flow schematic diagram that harmonic electric energy meter corrects in the present embodiment.
Fig. 4 is the structural schematic diagram of concrete application of the present invention three phase harmonic electric energy metering device used in the examples.
Fig. 5 is the test interface schematic diagram built in concrete application embodiment of the present invention.
Specific embodiment
Below in conjunction with Figure of description and specific preferred embodiment, the invention will be further described, but not therefore and
It limits the scope of the invention.
As shown in Figure 1, three phase harmonic electric energy gauging method of the present embodiment based on composite window multiline FFT, step include:
S1. the voltage in power grid, current signal are acquired and is converted to digital signal output；
S2. signal step S1 exported is carried out windowing FFT processing using composite window and is carried out based on multi-thread spectrum interpolation humorous
The parameter of fundamental wave, each harmonic is calculated in wave analysis, according to the parameter of calculated fundamental wave, each harmonic calculate fundamental wave and
Harmonic electric energy.
The present embodiment is detected for power grid dynamic harmonic and electrical energy measurement, carries out windows and interpolated FFT by using composite window,
The leakage of dynamic harmonic FFT spectrum and side lobe effect can be reduced, improves the leakage of dynamic harmonic FFT spectrum and side lobe performance, simultaneously
Traditional spectral line interpolation is improved, frequency analysis is carried out using multi-thread spectrum interpolation, the big spectral line of more accountings can be obtained, from
And more abundant, accurately characterization power network signal fundamental wave and harmonic wave characteristic, effectively improve the precision of three phase harmonic dynamic detection
And frequency spectrum resolving power.
In the present embodiment, in step S2 based on it is multi-thread spectrum interpolation carry out frequency analysis be to windowing FFT handle from
It dissipates more spectral lines in frequency spectrum near required frequency and carries out interpolation, building obtains fundamental wave, the amplitude of the parameter of each harmonic, frequency
Amendment type, fundamental wave, the amplitude of the parameter of each harmonic, frequency is calculated using the obtained amendment type of building.Carry out harmonic wave
When electrical energy measurement, the specific voltage acquired in power grid, current signal are converted to digital signal, obtain discrete series, this is discrete
Sequence carries out discrete Fourier transform and obtains discrete spectrum, to more spectral lines near frequency required in discrete spectrum (as required by
Spectral line near frequency left and right side) interpolation is carried out, amplitude, the frequency of You Gegen spectral line construct the width of fundamental wave, each harmonic parameter
The amendment type of value, frequency, by the available accurate fundamental wave of the amendment type, the amplitude of each harmonic parameter, frequency.
In the present embodiment, specifically used three spectral line interpolations that are based on carry out frequency analysis, based on the building amendment of three spectral line interpolations
The step of formula are as follows:
S21. taking the left and right spectral line of peak value spectral line and peak value spectral line is three spectral lines, according to the left and right spectral line of peak value spectral line
Amplitude between difference and peak value spectral line amplitude between contextual definition parameter γ, and the position according to peak value spectral line
And the difference defined parameters ε between the position of true peak spectral line；
S22. the width of multinomial G (ε) the building flicker envelope using the corresponding amplitude of three spectral lines and about parameter ε
The amendment type of value, frequency；
S23. it carries out curve fitting to amendment type, determines the approximant of the amendment type and multinomial G (ε) for obtaining parameter ε；
S24. the amplitude of flicker envelope, frequency amendment type in approached using the amendment type of parameter ε, multinomial G (ε)
Formula finally obtains the amplitude of the parameter of fundamental wave and each harmonic, the amendment type of frequency.
Three spectral lines that the present embodiment specifically takes the left and right spectral line of peak value spectral line and peak value spectral line to constitute carry out interpolation analysis
It calculates, the amendment type of the amplitude of flicker envelope, frequency is constructed by amplitude, the frequency according to three spectral lines, curve is used in combination
The mode of fitting obtains the wherein amendment type of parameter, polynomial approximant, to finally obtain fundamental wave and each harmonic
It is humorous to effectively improve nearby can to account for heavy 3 spectral line interpolations based on peak value spectral line for the amendment type of the amplitude of parameter, frequency
Wave analysis precision, while reducing computation complexity.
In the present embodiment, specifically used Blackman-Nuttall window w (n) carries out windowing process, Blackman-
Nuttall window can be further improved the secondary lobe of frequency analysis as a kind of cosine combination window with good side lobe performance
Energy.
The time-domain expression of Blackman-Nuttall window w (n) are as follows:
In formula, n=0,1 ..., N-1 (N is sampling number).
The discrete spectrum function of Blackman-Nuttall window are as follows:
If the power grid time-domain signal containing multiple harmonic are as follows:
In formula, H is the total degree containing harmonic wave；H is overtone order；As h=1, f0、A1、θ1The respectively frequency of fundamental wave
Rate, amplitude and initial phase angle；As h ≠ 1, Ah、θhThe respectively amplitude and initial phase angle of h subharmonic.
The signal x (t) that step S1 is output in the present embodiment is discrete series, be may be expressed as:
After signal x (n) is punctured into the sequence of N point using Blackman-Nuttall window w (n), discrete Fu is carried out to it
In leaf transformation its discrete spectrum can be obtained are as follows:
In formula, Δ f=fs/ N is discrete sampling interval.
Due to crest frequency f0=k0Δ f is typically not on the Frequency point of discrete spectral line, by the spectral line near peak value
Carrying out difference can get accurate signal amplitude parameter, and 3 spectral lines near peak value spectral line actually occupy greater weight,
The present embodiment considers above-mentioned characteristic, and by the way of Blackman-Nuttall window FFT and three spectral line interpolations, realization is based on
The mode that three spectral line of Blackman-Nuttall window improves FFT realizes frequency analysis, and the harmonic detecting of optimum performance may be implemented
Analysis.
The present embodiment combination Blackman-Nuttall window and three spectral line interpolation methods construct fundamental wave, each harmonic parameter
Amplitude and frequency amendment type detailed process are as follows:
If peak value spectral line is kthcItem and respective frequencies are kcΔ f, the left side spectral line of peak value spectral line are kc-1, the right adjacent spectral
Line is kc+1, true peak spectral line is kiAnd respective frequencies are fi, wherein correspond to fundamental wave as i=0, work as i=1, when 2,3 ...
Correspond to each harmonic, the corresponding amplitude of above-mentioned three spectral lines is respectively xc=| Y (kcΔ f) |, xc-1=| Y (kc-1Δ f) |, xc+1
=| Y (kc+1Δf)|；
Defined parameters γ are as follows:
And defined parameters ε=ki-kc, according to the parameter ε of definition, parameter ε is substituted into formula (6), can be obtained:
Wherein WBNFor the discrete spectrum for using Blackman-Nuttall window w (n)；
In the present embodiment, the amplitude m of flicker envelope is obtained with Simplified analysis by weight settingiAmendment type are as follows:
In formula: G (ε) is the multinomial about ε；
The frequency f of flicker envelopeiAmendment type are as follows:
fi=(kc+ε)Δf (9)
It using formula (8) and (9), is carried out curve fitting by MATLAB to multinomial, determines the amendment of obtained parameter ε
Approximant being respectively as follows: of formula, multinomial G (ε)
Formula (11) and (12) are substituted into formula (8) and (9) respectively, can be obtained the amplitude of the parameter of fundamental wave and each harmonic
mi, frequency fiAmendment type be respectively as follows:
By above-mentioned combination Blackman-Nuttall window and three spectral line interpolation methods, can construct to obtain measured signal
Fundamental wave and harmonic wave amplitude, phase and frequency amendment type, so as to accurately calculate power network signal fundamental wave and each time
Amplitude, the phase and frequency of harmonic component, can further be calculated fundamental wave and harmonic electric energy, realize accurate harmonic electric energy
Detection.
The detailed process of the present embodiment calculating fundamental wave and harmonic electric energy are as follows:
Under voltage harmonic distortion effects, network voltage current signal can regard the superposition of K sine wave, mathematical expression as
Formula are as follows:
The active power of unsinusoidal periodic quantity is equal to the active power that DC power component and fundamental wave and each harmonic are constituted
The sum of, it may be assumed that
In formula, P0For DC power component, P1=U1I1cosφ1For fundamental active power,For harmonic wave
Active power.
In sampling time T, fundamental active electric energy are as follows:
Similarly, harmonic wave active energy are as follows:
Fundamental wave, harmonic wave active energy is calculated, completes fundamental wave, harmonic electric energy metering.
It further include harmonic electric energy metering error aligning step in the present embodiment, after step S2 further to complete systematic error
Correction, harmonic electric energy metering error aligning step include: respectively when power factor is designated value, and what obtaining step S2 was obtained has
Function power measurement values and the active power standard value progress angular difference correction obtained using standard harmonic electric energy meter measurement, obtain base
Wave angle is poor, calculates step S2 according to calculated fundamental wave, harmonic wave according to obtained fundamental wave angular difference and uses standard harmonic electric energy meter
Measure obtained fundamental wave, the active power error between harmonic wave, harmonic voltage measurement error, harmonic current measurement error and humorous
Any one or more in wave phase measurement error, with the metric results of determination step S2 whether meet demand.
Error correction specifically includes angular difference and corrects two parts, voltage and current signals in power grid than difference in the present embodiment
After the analysis of above-mentioned windows and interpolated FFT, voltage and current is first carried out than difference correction, i.e., voltage, electric current is compared, obtains base
The virtual value of wave voltage and fundamental current is respectively U1′、I1′。
In the present embodiment, the specific steps of harmonic electric energy metering error correction are as follows:
The measured value of fundamental voltage and fundamental current that step S2 is obtained is respectively U1′、I1', use standard harmonic electric energy meter
Obtained standard value is respectively U1、I1, the phase difference between measured value and standard value is θ1, fundamental wave angular difference is φ1, fundamental active
The standard value P of power1With measured value P1' be respectively as follows:
P1=U1I1cosθ1 (20)
According to the standard value P of active power1With measured value P1By formula (20) and (21), ' obtain fundamental active error are as follows:
Angular difference calculates: choosing power factor and is tested for 1.0 with 0.5L two o'clock, passes through ratio when power factor is 1.0
It completes compared with measured value and corresponding standard scale indicating value than difference correction, when power factor is 0.5L according to θ1=π/3 substitutes into formula
(22) fundamental wave angular difference φ is obtained1:
Wherein, err0.5LFor fundamental wave active power factor 0.5L when error amount, which specifically can be by correction platform or people
Work test obtains.
In the present embodiment, angular difference school is specifically carried out using Newton interpolation method in harmonic electric energy metering error aligning step
Just, to carry out signal reconstruction to discrete sample sequence, S2 is re-execute the steps to re-start and add to the signal reconstructed
Window FFT, which is handled and is based on multi-thread spectrum interpolation, carries out frequency analysis, obtains final fundamental wave and harmonic wave Electric energy measurement.Newton inserts
Value is used as Curve fitting method, has the characteristics that arithmetic speed is high, calculation amount is few and is easy to programming, the present embodiment is based on
Single order Newton Interpolation Algorithm realizes angular difference correction, can further improve correction efficiency and precision, and can be convenient for practical engineering application,
By Newton Interpolation Algorithm can to discrete sample sequence carry out signal reconstruction, using reconstruct discrete sampling sequence of points again into
Row windows and interpolated FFT calculates the precision that can further improve measurement.
The use Newton interpolation method that the present embodiment uses is as shown in Fig. 2, y (n) indicates the actual sample value of nth point, y
(n-1) indicate that (n-1)th point of actual sample value, the time interval between two neighbouring sample points are 1/fs, y expression nth point
The time difference Δ t of theoretical sampled value, y (n) and y are then the angular differences for needing to correct
According to similar triangles theorem, have:
In formula, time interval is
The theoretical sampled value y closer to nth point is calculated according to nth point and (n-1)th point of actual sample value:
It enables
Wherein, M is correction coefficient, specifically can be by fundamental active power factor 0.5L that correction platform or manual testing obtain
When error amount seek.
There are many factor for influencing power and Electric energy measurement, such as component parameter deviation, temperature, proportional error and mutually
The phase shift etc. of sensor, the metric results accuracy of harmonic electric energy meter in addition to voltage and current signals sample circuit proportional error,
The phase shift that mutual inductor introduces is to influence maximum factor, and the detailed process of the present embodiment correction is as shown in figure 3, first use above-mentioned base
Frequency analysis is carried out in three spectral line interpolation FFT of Blackman-Nuttall window, after the active power of fundamental wave and harmonic wave is calculated,
Voltage and current is carried out than difference correction；Then it is tested 1.0 with 0.5L two o'clock, seeks fundamental wave angular difference, inserted using single-point newton
Value carries out sample sequence reconstruct, and the discrete series of reconstruct are re-started with the frequency analysis of adding window difference, wattful power is calculated
The parameters such as rate, active energy.
The three phase harmonic electric energy metering device based on composite window multiline FFT is further provided in the present embodiment, comprising:
Data acquisition unit, for acquiring the voltage in power grid, current signal and being converted to digital signal output；
Frequency analysis computing unit, the signal for exporting data acquisition unit are carried out at windowing FFT using composite window
Manage and be based on multi-thread spectrum interpolation and carry out frequency analysis, the parameter of fundamental wave, each harmonic is calculated, according to calculated fundamental wave,
The parameter of each harmonic calculates fundamental wave and harmonic electric energy.
As shown in figure 4, above-mentioned three phase harmonic electric energy metering device selects synchronous ADC+ in concrete application embodiment of the present invention
High-speed dsp+high-performance ARM architectural schemes, wherein ADC selects 8 Channel Synchronous to use ADC converter ADS1178, data processing
Unit core chips uses high-performance 32-bit floating type dsp processor TMS320C6745, and Data Management Unit core uses grace intelligence
The ARM chip K60 of Pu company, voltage signal and current signal in power grid are converted into meeting ADS1178 through signal conditioning circuit
The small voltage signal of input range, then the small voltage signal of simulation is converted into digital signal by ADS1178, digital signal passes through
The serial line interface of ADS1178 chip is sent to dsp chip TMS320C6745 and is handled in real time, is based on Blackman- by above-mentioned
Three spectral line fft algorithm of Nuttall window carries out frequency analysis to electric current and voltage waveform data and calculates, and obtains fundametal compoment and 2
The electric parameters such as~21 order harmonic components complete the precise measurement and electricity of every electric parameter by the high speed processing ability of DSP
The tasks such as energy metering；Result will finally be obtained, Data Management Unit K60 is sent to by SPI interface, completes real-time display, data
The work in every such as statistics, communication.
For the validity of the verifying above method of the present invention, device, a large amount of test and inspection are carried out by building actual measurement platform
It tests, the test interface of building is specifically as shown in Figure 5.
Typical test experiments are chosen, by taking fundamental power is superimposed 17 subharmonic power as an example, fundamental voltage is set as experiment test
220V, fundamental current are set as 1.5A, and the 17th subharmonic voltage amplitude is set as the 10% of fundamental voltage, the 17th subharmonic current amplitude
It is set as the 10% of fundamental current, the initial phase angle of harmonic voltage and harmonic current is set to 30 °, 20 °, and standard source is adopted as
Fluke6105A, the measuring result error of obtained fundamental active power error information, the 17th subharmonic amplitude and harmonic phase
As shown in table 1-3.
Table 1: fundamental active power error.
Table 2:17 subharmonic amplitude measurement data.
Table 3:17 subharmonic phase measurement data.
By table 1-3 it is found that fundamental active power error≤0.1%, harmonic voltage measurement error≤0.6%, harmonic current
Measurement error≤0.7%, harmonic phase measurement error≤0.5 ° meet the A rahmonic measuring instrument mark of GB/T-14549-93
Standard, i.e. the method for the present invention, device can effectively realize the accurate metering of the parameters such as active power and electric energy.
Above-mentioned only presently preferred embodiments of the present invention, is not intended to limit the present invention in any form.Although of the invention
It has been disclosed in a preferred embodiment above, however, it is not intended to limit the invention.Therefore, all without departing from technical solution of the present invention
Content, technical spirit any simple modifications, equivalents, and modifications made to the above embodiment, should all fall according to the present invention
In the range of technical solution of the present invention protection.
Claims (10)
1. a kind of three phase harmonic electric energy gauging method based on composite window multiline FFT, which is characterized in that step includes:
S1. the voltage in power grid, current signal are acquired and is converted to digital signal output；
S2. signal step S1 exported carries out windowing FFT processing using composite window and carries out harmonic wave point based on multi-thread spectrum interpolation
Analysis, is calculated the parameter of fundamental wave, each harmonic, calculates fundamental wave and harmonic wave according to the parameter of calculated fundamental wave, each harmonic
Electric energy.
2. three phase harmonic electric energy gauging method according to claim 1, which is characterized in that based on multi-thread in the step S2
Spectrum interpolation carry out frequency analysis be more spectral lines in the discrete spectrum handled the windowing FFT near required frequency into
Row interpolation, building obtain the amendment type of fundamental wave, the amplitude of the parameter of each harmonic, frequency, the amendment obtained using building
The fundamental wave, the amplitude of the parameter of each harmonic, frequency is calculated in formula.
3. three phase harmonic electric energy gauging method according to claim 2, which is characterized in that specifically used three spectral lines that are based on are inserted
The step of value carries out frequency analysis, constructs the amendment type based on three spectral line interpolations are as follows:
S21. taking the left and right spectral line of peak value spectral line and the peak value spectral line is three spectral line, according to the peak value spectral line
Difference between the amplitude of left and right spectral line and the contextual definition parameter γ between the amplitude of the peak value spectral line, and according to institute
State the difference defined parameters ε between the position of peak value spectral line and the position of true peak spectral line；
S22. the multinomial G (ε) using the corresponding amplitude of three spectral lines and about the parameter ε constructs flicker envelope
The amendment type of amplitude, frequency；
S23. it carries out curve fitting to the amendment type, determination obtains the amendment type and the multinomial G (ε) of the parameter ε
It is approximant；
S24. amendment type, the multinomial G of the parameter ε are used in the amplitude of the flicker envelope, the amendment type of frequency
(ε's) is approximant, finally obtains the amplitude of the parameter of fundamental wave and each harmonic, the amendment type of frequency.
4. three phase harmonic electric energy gauging method according to claim 3, which is characterized in that specifically used Blackman-
Nuttall window w (n) carries out windowing process, in the step S21, if peak value spectral line is kthcItem and respective frequencies are kcΔ f, institute
The left side spectral line for stating peak value spectral line is kc-1, the adjacent spectral line in the right is kc+1, true peak spectral line is kiAnd respective frequencies are fi,
In correspond to fundamental wave as i=0, work as i=1,2,3 ... when corresponds to each harmonic, the corresponding amplitude point of above-mentioned three spectral lines
It Wei not xc=| Y (kcΔ f) |, xc-1=| Y (kc-1Δ f) |, xc+1=| Y (kc+1Δf)|；
Defined parameters γ are as follows:
And defined parameters ε=ki-kc, parameter γ is obtained according to the parameter ε of definition and is met:
Wherein WBNFor the discrete spectrum for using Blackman-Nuttall window w (n)；
The amplitude m of the flicker envelope constructed in the step S22iAmendment type are as follows:
The frequency f of the flicker envelopeiAmendment type are as follows:
fi=(kc+ε)Δf。
5. three phase harmonic electric energy gauging method according to claim 4, which is characterized in that determining in the step S23
To the parameter ε amendment type, the multinomial G (ε) approximant being respectively as follows:
The γ -0.08172260 of ε=0.92240086 γ3+
0.01577433γ5-0.00331346γ7
G (ε)=1.64427532+0.45294290 ε2+
0.06655509ε4+0.00725154ε6
The amplitude m of the parameter of the fundamental wave obtained in the step S24 and each harmonici, frequency fiAmendment type difference
Are as follows:
mi=(2xC+xC-1+xc+1)N-1·
(1.64427532+0.45294290ε2+
0.06655509ε4+0.00725154ε6)
fi=(kc+0.92240086γ-0.08172260γ3+
0.01577433γ5-0.00331346γ7)Δf。
6. three phase harmonic electric energy gauging method described according to claim 1~any one of 5, which is characterized in that the step
It further include harmonic electric energy metering error aligning step after rapid S2, comprising: respectively when power factor is designated value, obtain the step
The wattful power messurement value and carry out angle using the active power standard value that standard harmonic electric energy meter measurement obtains that rapid S2 is obtained
Difference correction, obtains fundamental wave angular difference, calculates the step S2 according to calculated fundamental wave, harmonic wave according to the obtained fundamental wave angular difference
With the fundamental wave for using standard harmonic electric energy meter measurement to obtain, the active power error between harmonic wave, harmonic voltage measurement error, humorous
Any one or more in wave current measurement errors and harmonic phase measurement error, to determine the metering knot of the step S2
Fruit whether meet demand.
7. three phase harmonic electric energy gauging method according to claim 6, which is characterized in that the harmonic electric energy metering error
The specific steps of correction are as follows:
The measured value of fundamental voltage and fundamental current that step S2 is obtained is respectively U1′、I1', it is obtained using standard harmonic electric energy meter
Standard value be respectively U1、I1, the phase difference between the measured value and the standard value is θ1, fundamental wave angular difference is φ1, fundamental wave
The standard value P of active power1With measured value P1' be respectively as follows:
P1=U1I1cosθ1
P1'=U1′I1′cos(θ1+φ1)
=U1I1cos(θ1+φ1)
According to the standard value P of the active power1With measured value P1' obtain fundamental active error are as follows:
It chooses power factor to be tested for 1.0 with 0.5L two o'clock, when power factor is 1.0 by comparing measured value and accordingly
Standard scale indicating value complete than difference correction, power factor be 0.5L when according to θ1=π/3 and the fundamental active error obtain
To fundamental wave angular difference φ1:
Wherein, err0.5LFor fundamental wave active power factor 0.5L when error amount.
8. three phase harmonic electric energy gauging method according to claim 6, which is characterized in that the harmonic electric energy metering error
Angular difference correction is specifically carried out using Newton interpolation method in aligning step, it is right to carry out signal reconstruction to discrete sample sequence
The signal reconstructed re-execute the steps S2 to re-start windowing FFT and handle and be based on multi-thread spectrum interpolation progress harmonic wave and divide
Analysis, obtains final fundamental wave and harmonic wave Electric energy measurement.
9. three phase harmonic electric energy gauging method according to claim 8, it is characterised in that: described to use Newton interpolation method
The step of carrying out angle correct are as follows:
Actual sample value y (n), (n-1)th point of the actual sample value y (n-1) for obtaining nth point, according to nth point and (n-1)th point
Theoretical sampled value y is calculated in actual sample value:
It enables
Wherein M is correction coefficient, err0.5LError amount when for fundamental active power factor 0.5L.
10. a kind of three phase harmonic electric energy metering device based on composite window multiline FFT characterized by comprising
Data acquisition unit, for acquiring the voltage in power grid, current signal and being converted to digital signal output；
Frequency analysis computing unit, the signal for exporting the data acquisition unit are carried out at windowing FFT using composite window
Manage and be based on multi-thread spectrum interpolation and carry out frequency analysis, the parameter of fundamental wave, each harmonic is calculated, according to calculated fundamental wave,
The parameter of each harmonic calculates fundamental wave and harmonic electric energy.
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111178618A (en) * | 2019-12-25 | 2020-05-19 | 国网天津市电力公司电力科学研究院 | Intelligent power grid load prediction method |
| CN111458562A (en) * | 2020-04-15 | 2020-07-28 | 国网江苏省电力有限公司宿迁供电分公司 | Spectral peak reliability judgment method in harmonic analysis based on difference quotient |
| CN112014639A (en) * | 2020-09-02 | 2020-12-01 | 安徽一天电能质量技术有限公司 | Alternating current power harmonic direction measurement method |
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| CN113063987A (en) * | 2021-03-26 | 2021-07-02 | 湖南大学 | Broadband frequency coupling admittance on-line measurement method and system of power electronic equipment |
| CN113608023A (en) * | 2021-08-18 | 2021-11-05 | 国网湖南省电力有限公司 | Sampling frequency self-adaptive harmonic detection method and system |
| CN113625048A (en) * | 2021-08-19 | 2021-11-09 | 杭州万高科技股份有限公司 | Smart electric meter chip and smart electric meter |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102435845A (en) * | 2011-10-19 | 2012-05-02 | 广西电网公司电力科学研究院 | Harmonic energy metering method of Nuttall self-convolution weighted Fourier transform |
| CN104897961A (en) * | 2015-06-17 | 2015-09-09 | 中南民族大学 | Three spectral line interpolation FFT harmonic wave analysis method and system based on multiplication window function |
-
2019
- 2019-01-29 CN CN201910087192.7A patent/CN109633262A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102435845A (en) * | 2011-10-19 | 2012-05-02 | 广西电网公司电力科学研究院 | Harmonic energy metering method of Nuttall self-convolution weighted Fourier transform |
| CN104897961A (en) * | 2015-06-17 | 2015-09-09 | 中南民族大学 | Three spectral line interpolation FFT harmonic wave analysis method and system based on multiplication window function |
Non-Patent Citations (4)
| Title |
|---|
| 卿柏元: "谐波电能计量改进FFT算法研究", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
| 季冰: "基于ICA消噪技术和加窗插值FFT算法的电力系统谐波分析", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
| 宋慧娜 等: "一种高精度动态角差补偿算法", 《电测与仪表》 * |
| 郭振涛 等: "一种改进加窗三峰插值快速傅立叶变换谐波分析方法", 《上海电机学院学报》 * |
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