CN206788245U - A kind of harmonic electric energy metering module based on special digital wave filter - Google Patents
A kind of harmonic electric energy metering module based on special digital wave filter Download PDFInfo
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Abstract
A kind of harmonic electric energy metering module based on special digital wave filter is the utility model is related to, harmonic electric energy metering module is realized by FPGA, is divided into active energy metering module and reactive energy measurement module two parts；Active energy metering module includes special digital filter module, multiplication module, accumulator module, divider module, parallel adder module；Wherein, reactive energy measurement module only need to add a Hilbert wave filter to realize the phase shift of pi/2 on the basis of active energy metering module, i.e., increase a Hilbert digital filter block between voltage module and the first special digital filter module.The utility model can use relatively small number of hardware resource, obtain relatively good separating effect, comparatively save hardware area, thus be adapted to ASIC to realize.
Description
Technical field
A kind of harmonic electric energy metering module based on special digital wave filter of the utility model, is related to a kind of signal transacting skill
Art field, the FPGA of particularly a kind of harmonic electric energy metering module based on special digital wave filter are realized.
Background technology
Electric energy is the very important energy in human being's production life, and electric energy supply and Expenditure Levels need to pass through electric energy metrical
To realize.The task of electric energy metrical is that the instantaneous power of user is accurately summed into energy, be electricity power enterprise, power transmission and distribution enterprise,
The clearing that carried on trade between power consumer provide foundation, and the accuracy and reasonability of electric energy metrical also directly affect the economy of three
Interests and the fairness of transaction.
With the fast development of Power Electronic Technique, because the high-power silicon rectifier of electric railway and electrolysis plant is set
Standby, steel-making alternating current-direct current electric arc furnaces and AC inverter, high-power electric driven equipment, furnace of calcium carbide and motor variable-frequency speed-regulating device
Deng extensive use, a large amount of power equipments with nonlinear characteristic, which are put into power network, to be run, and makes industrial nonlinear load rapid
Increase, power network signal waveform Severe distortion, substantial amounts of harmonic wave occur in power network, cause Harmonious Waves in Power Systems to pollute, at the same it is also tight
The accuracy of electric energy metrical is affected again.Study harmonic electric energy metering module the purpose of be exactly in order to realize the Accurate Analysis of harmonic wave with
And the accurate metering of harmonic electric energy, provide reliable basis for the scientific management of electric energy.
Electric harmonic directly affects the accuracy and fairness of electric energy metrical.Harmonic electric energy metering method is accompanied by exchanging
What power system development got up, the frequency domain theory that has been born and when domain theory, form a variety of harmonic electric energy metering methods.Wherein base
It is that current application is most to be measured in the harmonic electric energy of Fourier transform (FFT), and a kind of widest method, but is still suffered from frequently
Phenomena such as rate aliasing, spectrum leakage and fence effect, while the operand of the module and amount of storage are also larger, influence harmonic wave metering
The degree of accuracy.
With the development of digital signal processor (DSP) and FPGA (FPGA), using DSP+
FPGA digital hardware system shows its superiority, is just more and more obtaining people's attention.The characteristics of DSP+FPGA structure maximums
It is flexible structure, there is stronger versatility, suitable for modularized design, so as to improves efficiency of algorithm；Its construction cycle simultaneously
Shorter, system is easy to maintain and extends, and is suitable for real time signal processing.It is improved to harmonic electric energy metering module at present to realize greatly
Majority is based on the MATLAB analog simulation stages, and the utility model is intended to complete a kind of harmonic electric energy based on special digital wave filter
The FPGA of metering module is realized.
Utility model content
The utility model proposes a kind of harmonic electric energy metering module based on special digital wave filter, it is therefore intended that in electricity
In the case of net frequency fluctuation, the degree of accuracy and the practicality of harmonic electric energy metering are improved.Solves the problems, such as harmonic electric energy measuring accuracy
Key：First, suppressing the higher fundamental signal of energy, its energy is set not to be leaked in the relatively low harmonic components of energy；Second,
In the case of ensureing mains frequency fluctuation, it is higher accurate that fundamental energy metric results remain in that with harmonic electric energy metric results
Degree.
The utility model is set about from problem one, and the method for solution is：A special digital wave filter is designed, in fundamental signal
During harmonic Signal separator, the decay to fundamental signal is sufficiently large, make fundamental signal be leaked to less as far as possible harmonic wave into
In point, interference is reduced.Conventional fft algorithm and wavelet packet decomposition algorithm are not carried out at single filtering to fundamental signal
Reason, therefore, it is necessary to pay bigger cost on the problem of suppressing fundamental wave leakage, and if filtered using a kind of special digital
Device is first by fundamental signal harmonic Signal separator, it is possible to relatively little of hardware resource, obtains relatively good separating effect.
The utility model is achieved through the following technical solutions above-mentioned purpose：A kind of harmonic wave electricity based on special digital wave filter
Energy metering module, is divided into active energy metering module and reactive energy measurement module two parts, wherein active energy metering module
As shown in Figure 1；Reactive energy measurement module only need to active energy metering on the basis of plus a Hilbert wave filter realize π/
2 phase shift, as shown in Figure 2.
Wherein, active energy metering module includes special digital filter module, multiplication module, accumulator module, removed
Summer block, parallel adder module, as shown in figure 1,
Voltage module and current module connect the first special digital filter module and the second special digital wave filter respectively
Module, the first special digital filter module are connected with the first multiplication module and the second multiplication module respectively, and second is special
Digital filter block is connected with the first multiplication module and the second multiplication module respectively, and the first multiplier connects the first division
Device module, export fundamental active Electric energy measurement；Second multiplier is sequentially connected accumulator module and the second divider module,
The metric results of output harmonic wave active energy.
Become as shown in Fig. 2 reactive energy measurement module only need to be a Hilbert more to the voltage or current signal of input
Phase shift is changed, i.e., increases a Hilbert digital filter block between voltage module and the first special digital filter module,
The phase shift of 90 ° of voltage signal is realized, is then equally handled according to the method for active energy metering module, you can obtain fundamental wave reactive power
The result of Electric energy measurement harmonic reactive energy measurement.
Wherein, the special digital filter module of design includes and takes the low pass filter of fundamental wave, goes the high-pass filtering of fundamental wave
Device and the harmonic wave bandpass filter group three parts for separating different frequency harmonic wave.
Wherein, the elliptic filter that described special digital filter module is selected in cascade connection type IIR type digital filters
The module is designed, separates each harmonic signal, the filtering process of different weights is employed to fundamental signal harmonic signal, and
Only consider that the several odd harmonics of a relatively high to harmonic energy do metering computing and storage during harmonic wave measures.
Wherein, the low pass filter of fundamental wave is taken, in order to ensure measuring accuracy, takes fundamental wave low pass filter design must be to height
Subharmonic has more than 30dB to decay, at the same when mains frequency fluctuation, in order to ensure that the metric results of fundamental wave are unaffected, low pass
Wave filter must make fundamental signal have flat amplitude-frequency response characteristic in the range of ± 5% (47.5Hz-52.5Hz).According to above-mentioned
Principle, choose low pass filter design parameter：6 rank IIR cascade connection type elliptic filters, sample frequency 3200Hz, passband cutoff frequency
Rate 65Hz, stopband attenuation 30Hz, passband ripple 0.0001dB.
Wherein, the high-pass filter of fundamental wave is removed, the energy of fundamental signal accounts for the 90% of power network gross energy in power network, therefore is
The influence that fundamental wave component is measured to harmonic wave is prevented, goes the fundamental wave high-pass filter there must be more than 50dB decay to fundamental wave, and
And there is flat amplitude-frequency response in more than 100Hz.According to mentioned above principle, high-pass filter design parameter is chosen：6 rank cascade connection types
IIR elliptic filters, sample frequency 3200Hz, cut-off frequency 90Hz, stopband attenuation 50dB, passband ripple 0.001dB.
Wherein, the effect of harmonic wave bandpass filter is to separate the harmonic components of different frequency.In order to reduce operand and saving
Memory cell, used in the design of harmonic wave radio station wave filter and realize the relatively small second-order bandpass filter of cost in harmonic electric energy
The relatively large several odd harmonics of energy individually extract.
Harmonic electric energy metering module of the present utility model, in addition to high-pass filter has 50dB or so decay to fundamental wave,
Bandpass filter further to fundamental signal can be decayed, about 30dB or so.Therefore fundamental signal is total in the module
Co-suppression 80dB or so, substantially exclude interference of the fundamental signal to harmonic signal.
Described Hilbert digital filter blocks, Hilbert digital filter blocks are provided using altera corp
FIR IP kernels are realized, are to wait the FIR types digital filter design of the ripple Chebyshev method module using advantest method, are utilized nothing
Work(power and active power are the theoretical foundation of 90 ° of carrier phase shift, by being done to the instantaneous value of input voltage or electric current
Hilbert converts phase shiftReactive power is calculated with phase-shifting method.
A kind of harmonic electric energy metering module based on special digital wave filter of the utility model, its advantage are：
1. the utility model proposes a kind of special harmonic electric energy metering module for being more suitable for ASIC realizations, devise special
Digital filter block.The filtering process of different weights is employed to fundamental signal harmonic signal, and in harmonic wave metering
During only consider that the several odd harmonics of a relatively high to harmonic energy do metering computing and storage, and more often apply at present
Interpolating Window FFT Algorithm and wavelet packet decomposition algorithm use the computing of equal weight, this method to fundamental signal harmonic signal
One times is added compared with its operand, but amount of storage only has the two 1/10th, can use relatively small number of hardware resource, obtains
Relatively good separating effect, hardware area is comparatively more saved, thus be more suitable for ASIC realizations.
2. the utility model studies the design method of Hilbert digital filters, preferably ripple is waited to cut ratio from effect
Xue Fufa designs Hilbert digital filters.
3. the utility model realizes harmonic electric energy metering module, including active electric energy metering module and idle electricity on FPGA
Can metering module.The measurement result of analysis module is discussed, draws final sumbission.
4. special digital filter module and Hilbert numerals are realized on the EP2C35F672C8 chips of altera corp
Filter module.Special digital filter module is automatically generated using being modeled under MATLAB environment using DSP Builder
The modes of VHDL codes is realized；FIR IP kernels that Hilbert digital filter blocks are provided using altera corp are realized.
Brief description of the drawings
The harmonic wave active energy metering module that Fig. 1 uses for the utility model realizes block diagram.
The harmonic wave reactive energy measurement module that Fig. 2 the utility model uses realizes block diagram.
The design structure diagram of Fig. 3 special digital filter modules of the present utility model.
Embodiment
To make the purpose of this utility model, technical scheme and advantage clearer, the present invention is implemented below in conjunction with the accompanying drawings
Example is described in further detail.
A kind of harmonic electric energy metering module based on special digital wave filter, is divided into active energy metering module and idle electricity
Energy metering module two parts, wherein active energy metering module are as shown in Figure 1；Reactive energy measurement module only need to be in active energy
On the basis of metering plus a Hilbert wave filter realizes the phase shift of pi/2, as shown in Figure 2.
Wherein, active energy metering module includes special digital filter module, multiplication module, accumulator module, removed
Summer block, parallel adder module, as shown in figure 1,
Voltage module and current module connect the first special digital filter module and the second special digital wave filter respectively
Module, the first special digital filter module are connected with the first multiplication module and the second multiplication module respectively, and second is special
Digital filter block is connected with the first multiplication module and the second multiplication module respectively, and the first multiplier connects the first division
Device module, export fundamental active Electric energy measurement；Second multiplier is sequentially connected accumulator module and the second divider module,
The metric results of output harmonic wave active energy.
Idiographic flow is：
(1) by voltage and current signal respectively simultaneously input special digital wave filter, as a result respectively export fundamental signal and
Relatively large several odd harmonic signals.
(2) the fundamental voltage sample that special digital wave filter exports is multiplied with the input of fundamental current sample
Summer block, the instantaneous voltage of several odd harmonics of harmonic wave bandpass filter group output and current instantaneous value input are multiplied
Summer block.
(3) multiplying is carried out to instantaneous voltage and current instantaneous value by multiplication module, obtains the wink at the moment
When performance number.
(4) fundamental wave instantaneous power value obtains fundamental active Electric energy measurement, the instantaneous work(of harmonic wave by accumulator, divider
Rate value obtains the metric results of harmonic wave active energy by accumulator, parallel adder and divider.
Similarly, as shown in Fig. 2 reactive energy measurement module only need to do one more to the voltage or current signal of input
Hilbert converts phase shift, i.e., one Hilbert numeral filter of increase between voltage module and the first special digital filter module
Ripple device module, the phase shift of 90 ° of voltage signal is realized, then equally handled according to the method for active energy metering module, you can
To the result of fundamental wave reactive power Electric energy measurement harmonic reactive energy measurement.
Wherein, the special digital filter module of design includes and takes the low pass filter of fundamental wave, goes the high-pass filtering of fundamental wave
Device and the harmonic wave bandpass filter group three parts for separating different frequency harmonic wave.As shown in figure 3, idiographic flow is：
(1) after voltage and current signal input special digital wave filter, first fundamental wave low pass filter and fundamental wave are passed through simultaneously
High-pass filter, fundamental signal harmonic Signal separator is come and exported.
(2) harmonic signal of output is also needed to by harmonic wave bandpass filter group, relatively large several strange of output energy
Rd harmonic signal, so far fundamental wave and harmonic signal are realized and separated.
The elliptic filter design that described special digital filter module is selected in cascade connection type IIR type digital filters should
Module, each harmonic signal is separated, the filtering process of different weights is employed to fundamental signal harmonic signal, and in harmonic wave
Only consider that the several odd harmonics of a relatively high to harmonic energy do metering computing and storage during metering.
Wherein, the low pass filter of fundamental wave is taken, in order to ensure measuring accuracy, takes fundamental wave low pass filter design must be to height
Subharmonic has more than 30dB to decay, at the same when mains frequency fluctuation, in order to ensure that the metric results of fundamental wave are unaffected, low pass
Wave filter must make fundamental signal have flat amplitude-frequency response characteristic in the range of ± 5% (47.5Hz-52.5Hz).According to above-mentioned
Principle, choose low pass filter design parameter：6 rank IIR cascade connection type elliptic filters, sample frequency 3200Hz, passband cutoff frequency
Rate 65Hz, stopband attenuation 30Hz, passband ripple 0.0001dB.
Wherein, the high-pass filter of fundamental wave is removed, the energy of fundamental signal accounts for the 90% of power network gross energy in power network, therefore is
The influence that fundamental wave component is measured to harmonic wave is prevented, goes the fundamental wave high-pass filter there must be more than 50dB decay to fundamental wave, and
And there is flat amplitude-frequency response in more than 100Hz.According to mentioned above principle, high-pass filter design parameter is chosen：6 rank cascade connection types
IIR elliptic filters, sample frequency 3200Hz, cut-off frequency 90Hz, stopband attenuation 50dB, passband ripple 0.001dB.
Wherein, the effect of harmonic wave bandpass filter is to separate the harmonic components of different frequency.In order to reduce operand and saving
Memory cell, used in the design of harmonic wave radio station wave filter and realize the relatively small second-order bandpass filter of cost in harmonic electric energy
The relatively large several odd harmonics of energy individually extract.
Harmonic electric energy metering module of the present utility model, in addition to high-pass filter has 50dB or so decay to fundamental wave,
Bandpass filter further to fundamental signal can be decayed, about 30dB or so.Therefore fundamental signal is total in the module
Co-suppression 80dB or so, substantially exclude interference of the fundamental signal to harmonic signal.
Described Hilbert digital filter blocks, Hilbert digital filter blocks are provided using altera corp
FIR IP kernels are realized, are to wait the FIR types digital filter design of the ripple Chebyshev method module using advantest method, are utilized nothing
Work(power and active power are the theoretical foundation of 90 ° of carrier phase shift, by being done to the instantaneous value of input voltage or electric current
Hilbert converts phase shiftReactive power is calculated with phase-shifting method.
Calculate active power formula be：
Wherein uh(n)、ih(n) h subharmonic voltages, current instantaneous value in power network signal are represented respectively；Δ t is adjacent
Time interval between sampled point.Understand, harmonic electric energy metering key be effectively extracted from power network signal each time it is humorous
Wave voltage harmony signal wave current.Instantaneous voltage, the current instantaneous value of same frequency mutually multiply accumulating, multiplied by with adjacent sampled point
Between time interval, you can obtain active energy metric results.Reactive energy measurement module needs the voltage or electric current to input
Signal does Hilbert 90 ° of phase shifts of conversion, is then handled according to active energy metering module.
The fpga chip that the utility model uses is the EP2C35F672C8 chips of altera corp Cyclone II series.
Active energy metering module takes the 33% of total resources, and reactive energy measurement module takes the 50% of total resources.Reactive energy meter
Amount module is compared with active energy metering module, has more the FIR type digital filters of 64 ranks, and coordinate the FIR type numbers
Other modules that word wave filter uses, thus than active energy metering module more take 17% hardware resource.
Claims (7)
1. a kind of harmonic electric energy metering module based on special digital wave filter, harmonic electric energy metering module is realized by FPGA,
It is characterized in that：It is divided into active energy metering module and reactive energy measurement module two parts；
Wherein, active energy metering module includes special digital filter module, multiplication module, accumulator module, divider
Module, parallel adder module, it is specific as follows：
Voltage module and current module connect the first special digital filter module and the second special digital filter module respectively,
First special digital filter module is connected with the first multiplication module and the second multiplication module respectively, the filter of the second special digital
Ripple device module is connected with the first multiplication module and the second multiplication module respectively, and the first multiplier connects the first divider mould
Block, export fundamental active Electric energy measurement；Second multiplier is sequentially connected accumulator module and the second divider module, output
The metric results of harmonic wave active energy；
Wherein, reactive energy measurement module only need to add a Hilbert wave filter real on the basis of active energy metering module
The phase shift of existing pi/2, i.e., increase a Hilbert digital filter between voltage module and the first special digital filter module
Module.
A kind of 2. harmonic electric energy metering module based on special digital wave filter according to claim 1, it is characterised in that：
Described special digital filter module, which includes, to be taken the low pass filter of fundamental wave, goes the high-pass filter of fundamental wave and separation different
The harmonic wave bandpass filter group of frequency harmonics.
A kind of 3. harmonic electric energy metering module based on special digital wave filter according to claim 2, it is characterised in that：
The described low pass filter for taking fundamental wave is：6 rank IIR cascade connection type elliptic filters, sample frequency 3200Hz, cut-off frequecy of passband
65Hz, stopband attenuation 30Hz, passband ripple 0.0001dB.
A kind of 4. harmonic electric energy metering module based on special digital wave filter according to claim 2, it is characterised in that：
The described high-pass filter for removing fundamental wave is：6 rank cascade connection type IIR elliptic filters, sample frequency 3200Hz, cut-off frequency
90Hz, stopband attenuation 50dB, passband ripple 0.001dB.
A kind of 5. harmonic electric energy metering module based on special digital wave filter according to claim 2, it is characterised in that：
Described harmonic wave bandpass filter group uses and realizes the relatively small second-order bandpass filter of cost.
A kind of 6. harmonic electric energy metering module based on special digital wave filter according to claim 1, it is characterised in that：
The elliptic filter that described special digital filter module is selected in cascade connection type IIR type digital filters.
A kind of 7. harmonic electric energy metering module based on special digital wave filter according to claim 1, it is characterised in that：
The FIR IP kernels that described Hilbert digital filter blocks are provided using altera corp are realized.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109085425A (en) * | 2018-07-20 | 2018-12-25 | 国网湖南省电力有限公司 | A kind of impact load calculation method |
| CN112436529A (en) * | 2020-11-13 | 2021-03-02 | 南京斯坦艾德电气有限公司 | Extraction method and compensation device for active current of unbalanced load |
| CN113030570A (en) * | 2021-03-22 | 2021-06-25 | 宁夏隆基宁光仪表股份有限公司 | Harmonic electric energy detection method and adaptive filter |
-
2017
- 2017-06-14 CN CN201720689360.6U patent/CN206788245U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109085425A (en) * | 2018-07-20 | 2018-12-25 | 国网湖南省电力有限公司 | A kind of impact load calculation method |
| CN109085425B (en) * | 2018-07-20 | 2020-10-20 | 国网湖南省电力有限公司 | Impact load calculation method |
| CN112436529A (en) * | 2020-11-13 | 2021-03-02 | 南京斯坦艾德电气有限公司 | Extraction method and compensation device for active current of unbalanced load |
| CN113030570A (en) * | 2021-03-22 | 2021-06-25 | 宁夏隆基宁光仪表股份有限公司 | Harmonic electric energy detection method and adaptive filter |
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