CN104991104A - Power signal amplitude detection method and system - Google Patents

Abstract

The invention relates to a power signal amplitude detection method and system. Truncation processing is performed on the sampled signal sequences so that truncated signal sequences are obtained; a cosine function of the measured reference frequency and a sine function of the reference frequency are respectively multiplied by the signal sequences and the truncated signal sequences so that two sets of real frequency vector sequences and imaginary frequency vector sequences are generated; digital filtering is performed on the two sets of imaginary frequency vector sequences and the real frequency vector sequences so that two sets of imaginary number vector filtering sequences and real number vector filtering sequences are generated, and then two sets of imaginary number vector integral values and real number vector integral values are generated through integration; the two sets of real number vector integral values and the imaginary number vector integral values are converted into sequence amplitude and two phases, and the two phases are converted into frequency difference; and the sequence amplitude and the frequency difference are converted into fundamental wave amplitude of a power signal. The fundamental wave amplitude with relatively high accuracy can be obtained by application of the power signal amplitude detection method and system.

Description

The amplitude detection method and system of electric power signal

Technical field

The present invention relates to technical field of electric power, particularly relate to a kind of amplitude detection method and system of electric power signal.

Background technology

The frequency measurement, phase measurement, amplitude measurement etc. of electric system are the measurement of sinusoidal signal parameter in itself.Electric power signal is a kind of sinusoidal signal in itself, and Fourier transform etc. are the basic skills realizing sinusoidal signal parameter measurement, are widely used in electric system.But along with the development of parameter measurement techniques, Fourier transform Problems existing is also more aobvious outstanding, is difficult to the requirement meeting the calculating of electric system offset of sinusoidal parameter pin-point accuracy further.

In the parameter measurement of electric system sinusoidal signal, there is the measurement method of parameters be in various forms, as zero hands over method, based on the mensuration of filtering, based on Wavelet Transform, based on the mensuration of neural network, the mensuration etc. based on DFT conversion.

But the specified power frequency of operation of power networks is 50Hz, belongs to lower sinusoidal frequency, the sine parameter measuring accuracy of above-described sinusoidal signal measurement method of parameters to low frequency signal is low, and noise immunity is poor.

Summary of the invention

Based on this, be necessary for the sine parameter measuring accuracy of above-described sine parameter measuring method to low frequency signal low, and the problem of noise immunity difference, a kind of amplitude detection method and system of electric power signal is provided.

An amplitude detection method for electric power signal, comprises the following steps:

Calculate predetermined sequence length according to preset signals periodicity and default sample frequency, electric power signal is sampled, obtain the burst of predetermined sequence length;

Frequency preliminary survey is carried out to described burst, generates the first synchronizing frequency of described electric power signal, and with described just synchronizing frequency for reference frequency;

Carry out brachymemma process to described burst, obtain truncated signal sequence, the brachymemma value of the sequence length of the relatively described burst of sequence length of described truncated signal sequence is 0.25 times of 1 periodic sequence length of described burst;

Be multiplied with described burst respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generate the first real sequence vector frequently and the first empty sequence vector frequently;

Be multiplied with described truncated signal sequence respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generate the second real sequence vector frequently and the second empty sequence vector frequently;

Respectively digital filtering is carried out to the described first real sequence vector frequently and the described first empty sequence vector frequently, generate the first real wave-vector filtering sequence frequently and the first empty sequence of wave-vector filtering frequently;

Respectively integral operation is carried out to the described first real wave-vector filtering sequence frequently and the described first empty sequence of wave-vector filtering frequently, generate the first real vector product score value frequently and the first empty vector product score value frequently;

Respectively digital filtering is carried out to the described second real sequence vector frequently and the described second empty sequence vector frequently, generate the second real wave-vector filtering sequence frequently and the second empty sequence of wave-vector filtering frequently;

Respectively integral operation is carried out to the described second real wave-vector filtering sequence frequently and the described second empty sequence of wave-vector filtering frequently, generate the second real vector product score value frequently and the second empty vector product score value frequently;

According to the phase place preset and amplitude transformation rule, the described first empty vector product score value frequently and the described first real vector product score value are frequently converted to first phase and sequence amplitude;

According to the phase transition rule preset, the described second empty vector product score value frequently and the described second real vector product score value are frequently converted to second phase;

According to the frequency difference transformation rule preset, described first phase and described second phase are converted to the frequency difference of described frequency power signal and described reference frequency;

According to the amplitude transformation rule preset, the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency is converted to the fundamental voltage amplitude of described electric power signal.

An amplitude detection system for electric power signal, comprising:

Sampling module, for calculating predetermined sequence length according to preset signals periodicity and default sample frequency, sampling to electric power signal, obtaining the burst of predetermined sequence length;

Preliminary survey module, for carrying out frequency preliminary survey to described burst, generates the first synchronizing frequency of described electric power signal, and with described just synchronizing frequency for reference frequency;

Brachymemma module, for carrying out brachymemma process to described burst, obtain truncated signal sequence, the brachymemma value of the sequence length of the relatively described burst of sequence length of described truncated signal sequence is 0.25 times of 1 periodic sequence length of described burst;

First frequency mixing module, for being multiplied with described burst respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generates the first real sequence vector frequently and the first empty sequence vector frequently;

Second frequency mixing module, for being multiplied with described truncated signal sequence respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generates the second real sequence vector frequently and the second empty sequence vector frequently;

First filtration module, for carrying out digital filtering to the described first real sequence vector frequently and the described first empty sequence vector frequently respectively, generates the first real wave-vector filtering sequence frequently and the first empty sequence of wave-vector filtering frequently;

First integral module, for carrying out integral operation to the described first real wave-vector filtering sequence frequently and the described first empty sequence of wave-vector filtering frequently respectively, generates the first real vector product score value frequently and the first empty vector product score value frequently;

Second filtration module, for carrying out digital filtering to the described second real sequence vector frequently and the described second empty sequence vector frequently respectively, generates the second real wave-vector filtering sequence frequently and the second empty sequence of wave-vector filtering frequently;

Second integral module, for carrying out integral operation to the described second real wave-vector filtering sequence frequently and the described second empty sequence of wave-vector filtering frequently respectively, generates the second real vector product score value frequently and the second empty vector product score value frequently;

Phase-amplitude modular converter, for according to the phase place preset and amplitude transformation rule, is converted to first phase and sequence amplitude by the described first empty vector product score value frequently and the described first real vector product score value frequently;

Phase conversion, for according to the phase transition rule preset, is converted to second phase by the described second empty vector product score value frequently and the described second real vector product score value frequently;

Frequency difference modular converter, for according to the frequency difference transformation rule preset, is converted to the frequency difference of described frequency power signal and described reference frequency by described first phase and described second phase;

Amplitude modular converter, for according to the amplitude transformation rule preset, is converted to the fundamental voltage amplitude of described electric power signal by the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency.

The amplitude detection method and system of above-mentioned electric power signal, brachymemma process is carried out to the burst of sampling gained, obtain truncated signal sequence, the brachymemma value of the length of the relatively described burst of length of described truncated signal sequence is 0.25 times of signal period sequence length; With the cosine function of survey reference frequency be multiplied with described truncated signal sequence with described burst respectively with the sine function of described reference frequency, generate two groups of real sequence vectors frequently and empty sequence vectors frequently; By to two groups of empty sequence vectors frequently and real sequence vector digital filtering frequently, generate two groups of imaginary number wave-vector filtering sequences and real number wave-vector filtering sequence, and then integration generates two groups of imaginary number vector product score values and real number vector product score value; Again according to the phase transition rule preset, two groups of real number vector product score values and imaginary number vector product score value are converted to sequence amplitude and two phase places, according to the frequency difference transformation rule preset, be the frequency difference of described frequency power signal and described reference frequency by two phase transition; According to the amplitude transformation rule preset, the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency is converted to the fundamental voltage amplitude of described electric power signal, there is higher accuracy.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet of amplitude detection method first embodiment of electric power signal of the present invention;

Fig. 2 is the structural representation of amplitude detection system first embodiment of electric power signal of the present invention;

Fig. 3 is burst and the truncated signal sequence diagram of the amplitude detection method of electric power signal of the present invention;

Fig. 4 is that the fundamental voltage amplitude of the amplitude detection system of electric power signal of the present invention detects relative error experimental result schematic diagram.

Embodiment

In order to make the object, technical solutions and advantages of the present invention clearly, below in conjunction with accompanying drawing, the present invention is described in further detail.

Although the step in the present invention arranges with label, and be not used in and limit the precedence of step, the order of step or the execution of certain step need based on other steps unless expressly stated, otherwise the relative rank of step is adjustable.

Refer to Fig. 1, Fig. 1 is the schematic flow sheet of amplitude detection method first embodiment of electric power signal of the present invention.

The amplitude detection method of the described electric power signal of present embodiment can comprise the following steps:

Step S101, calculates predetermined sequence length according to preset signals periodicity and default sample frequency, samples to electric power signal, obtain the burst of predetermined sequence length.

Step S102, carries out frequency preliminary survey to described burst, generates the first synchronizing frequency of described electric power signal, and with described just synchronizing frequency for reference frequency.

Step S103, carries out brachymemma process to described burst, and obtain truncated signal sequence, the brachymemma value of the sequence length of the relatively described burst of sequence length of described truncated signal sequence is 0.25 times of 1 periodic sequence length of described burst.

Step S104, is multiplied with described burst with the sine function of described reference frequency respectively with the cosine function of described reference frequency, generates the first real sequence vector frequently and the first empty sequence vector frequently.

Step S105, is multiplied with described truncated signal sequence with the sine function of described reference frequency respectively with the cosine function of described reference frequency, generates the second real sequence vector frequently and the second empty sequence vector frequently.

Step S106, carries out digital filtering to the described first real sequence vector frequently and the described first empty sequence vector frequently respectively, generates the first real wave-vector filtering sequence frequently and the first empty sequence of wave-vector filtering frequently.

Step S107, carries out integral operation to the described first real wave-vector filtering sequence frequently and the described first empty sequence of wave-vector filtering frequently respectively, generates the first real vector product score value frequently and the first empty vector product score value frequently.

Step S108, carries out digital filtering to the described second real sequence vector frequently and the described second empty sequence vector frequently respectively, generates the second real wave-vector filtering sequence frequently and the second empty sequence of wave-vector filtering frequently.

Step S109, carries out integral operation to the described second real wave-vector filtering sequence frequently and the described second empty sequence of wave-vector filtering frequently respectively, generates the second real vector product score value frequently and the second empty vector product score value frequently.

Step S110, according to the phase place preset and amplitude transformation rule, is converted to first phase and sequence amplitude by the described first empty vector product score value frequently and the described first real vector product score value frequently.

Step S111, according to the phase transition rule preset, is converted to second phase by the described second empty vector product score value frequently and the described second real vector product score value frequently.

Step S112, according to the frequency difference transformation rule preset, is converted to the frequency difference of described frequency power signal and described reference frequency by described first phase and described second phase.

Step S113, according to the amplitude transformation rule preset, is converted to the fundamental voltage amplitude of described electric power signal by the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency.

Present embodiment, carry out brachymemma process to the burst of sampling gained, obtain truncated signal sequence, the brachymemma value of the length of the relatively described burst of length of described truncated signal sequence is 0.25 times of signal period sequence length; With the cosine function of survey reference frequency be multiplied with described truncated signal sequence with described burst respectively with the sine function of described reference frequency, generate two groups of real sequence vectors frequently and empty sequence vectors frequently; By to two groups of empty sequence vectors frequently and real sequence vector digital filtering frequently, generate two groups of imaginary number wave-vector filtering sequences and real number wave-vector filtering sequence, and then integration generates two groups of imaginary number vector product score values and real number vector product score value; Again according to the phase transition rule preset, two groups of real number vector product score values and imaginary number vector product score value are converted to sequence amplitude and two phase places, according to the frequency difference transformation rule preset, be the frequency difference of described frequency power signal and described reference frequency by two phase transition; According to the amplitude transformation rule preset, the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency is converted to the amplitude of described electric power signal, there is higher accuracy.

Afterwards if do not added explanation, the amplitude of described electric power signal all refers to the fundamental voltage amplitude of electric power signal.

Wherein, for step S101, preferably, described preset signals periodicity is set according to actual needs.Described preset signals periodicity can be integer 11, because there is error, integer 11 is about.

Further, electric system rated frequency 50Hz, in order to improve performance, sample frequency much larger than 50Hz, should can arrange described default sample frequency f _n=10KHz, sampling interval is expressed as formula (1):

$T_n=\frac{1}{f_n}---\left(1\right);$

Wherein, T _nfor sampling interval, unit s; f _nfor described default sample frequency, unit Hz.

In one embodiment, by the following stated formula (2), described preset signals periodicity and described default sample frequency are converted to described predetermined sequence length:

N＝(int)C _2πT _2πf _n(2)；

Wherein, N is burst length, unit dimensionless; (int) be round numbers; C _{2 π}for preset signals periodicity, unit dimensionless; T _{2 π}for the signal period, unit s.

Actual in the described reference frequency calculating signal period, there is error.

Described burst, shown in Fig. 3.To single detection frequency signal, described burst is expressed as formula (3):

Wherein, X _in () is burst; A is signal fundamental voltage amplitude, unit v; ω is signal frequency, unit rad/s; T _nfor sampling interval, unit s; N is series of discrete number, unit dimensionless; for signal initial phase, unit rad, N are described predetermined sequence length, unit dimensionless.

For step S102, by zero friendship method, frequency preliminary survey is carried out to described burst, obtain described just synchronizing frequency.Also by other frequency measurement methods that those skilled in the art are usual, frequency preliminary survey is carried out to described input signal sequence.

Described preliminary frequency is expressed as formula (4):

ω _o(4)；

Wherein, ω _ofor first synchronizing frequency, unit rad/s;

Preferably, described reference frequency is expressed as formula (5):

ω _s＝ω _o(5)；

Wherein, ω _sfor reference frequency, unit rad/s; ω _ofor first synchronizing frequency, unit rad/s.

For step S103, preferably, described truncated signal sequence length is expressed as formula (6):

N _S＝N-0.25N _2π(6)；

In formula, N _sfor truncated signal sequence length, unit dimensionless; N _{2 π}for signal unit periodic sequence length, unit dimensionless.

Preferably, calculate signal unit periodic sequence length according to described reference frequency, be formula (7):

$N_{2\mathrm{\π}}=\left(\mathrm{int}\right)\frac{2\mathrm{\π}}{{\mathrm{\ω}}_s{T}_n}---\left(7\right);$

Wherein, (int) represents round numbers, signal unit periodic sequence length N _{2 π}there is the error in 1 sampling interval in integer.

Described truncated signal sequence, shown in Fig. 3, the expression formula of described truncated signal sequence is formula (8):

In formula, X ₂n () is truncated signal sequence.

For step S104, preferably, the cosine function of described reference frequency and the sine function of described reference frequency can be respectively with described reference frequency be frequency, with T _nfor sine function and the cosine function of spaced discrete variable.

In one embodiment, described first real sequence vector frequently and the described first empty sequence vector is frequently multiplied respectively with described burst for formula (9) with the cosine function of described reference frequency and the sine function of described reference frequency:

Wherein, R ₁n () is the described first real sequence vector frequently; I ₁n () is the described first empty sequence vector frequently; Ω is the frequency difference of signal frequency and reference frequency, unit rad/s; with for active constituent; with for mixing interfering frequency composition.

For step S105, be multiplied with described truncated signal sequence respectively with the sine function of described reference frequency with the cosine function of described reference frequency, obtain described second real sequence vector frequently and the described second empty sequence vector is frequently formula (10):

In formula, R ₂n () is the described second real sequence vector frequently; I ₂n () is the described second empty sequence vector frequently; Ω is the frequency difference of signal frequency and reference frequency, unit rad/s; with for active constituent; with for mixing interfering frequency composition.

For step S106, in the described first real sequence vector frequently and the described first empty sequence vector frequently, comprise mixing interfering frequency.When in input signal also at flip-flop, subharmonic composition and subharmonic composition time, described mixing interfering frequency will be more complicated, and these mixing interfering frequencies have a strong impact on accuracy in computation.Although window function and integral operation itself have good attenuation to mixing interfering frequency, do not have specific aim, can not produce the inhibiting effect of the degree of depth to the mixing interfering frequency of described complexity, the pin-point accuracy that can not meet parameter calculates needs.

In order to suppress the impact of described mixing interfering frequency targetedly, adopt a kind of digital filter, ideally, the null Frequency point just in time corresponding described mixing interfering frequency point of digital filter, has inhibiting effect completely to described mixing interfering frequency.Preferably, digital filtering specifically adopts digital averaging filtering algorithm, is added, then gets its arithmetic mean and export as this filter value by several continuous discrete values.Digital filtering needs to arrange digital filter parameters, and described digital filter parameters refers to the length N that several continuous discrete values are added _d.At digital filter parameters N _dvalue is 1.5 times of signal period sequence length, can suppress the mixing interfering frequency that 1/3 subharmonic produces.And N _dvalue is 2 times of signal period sequence length, can to direct current, 1/2 gradation, 1 time, 2 times, 3 times, 4 times, the mixing interfering frequency that produces such as 5 subharmonic suppresses.Therefore, digital filtering is made up of the digital filter of 2 kinds of parameters, considers the factors such as physical presence error, in order to the degree of depth suppresses the impact of mixing interfering frequency, the digital filter of often kind of parameter forms by the three stages of digital filtering that parameter is identical, and totally six grades of arithmetic mean digital filterings formed.

Preferably, six grades of arithmetic mean digital filtering formulas can be formula (11):

Wherein, X (n) is digital filtering list entries, sequence length N; X _dn () is digital filtering output sequence, sequence length N-3N _d1-3N _d2; N _d1for filtering parameter 1, namely discrete value is added quantity continuously; N _d2for filtering parameter 2, namely discrete value is added quantity continuously.

In one embodiment, filtering parameter N _d1value is 1.5 times of the unit period sequence length of described reference frequency, filtering parameter N _d2value is 2 times of the unit period sequence length of described reference frequency, in one embodiment, and filtering parameter N _d1value is 1.5 times of the unit period sequence length of described reference frequency, filtering parameter N _d2value is 2 times of the unit period sequence length of described reference frequency, and six grades of arithmetic mean digital filterings need use 10.5 times of signal period sequence lengths.

Preferably, under described mixing interfering frequency composition is suppressed prerequisite completely, the described first real wave-vector filtering sequence frequently and the described first empty sequence of wave-vector filtering are frequently (12):

Wherein, R _d1(Ω) be the described first real sequence of wave-vector filtering frequently; I _d1(Ω) be the described first empty sequence of wave-vector filtering frequently; K (Ω) is for digital filtering is in the dimensionless gain of frequency difference Ω; α (Ω) for digital filtering is in the phase shift of frequency difference Ω, unit rad.

For step S107, preferably, integral operation formula is (13):

Wherein, R ₁it is the first real vector product score value frequently; I ₁it is the first empty vector product score value frequently.L1 is first integral length, unit dimensionless, and in principle, L1 is minimum is 0.5 times of signal period sequence length.

For step S108, in like manner and preferably, under described mixing interfering frequency composition is suppressed prerequisite completely, the described second real wave-vector filtering sequence frequently and the described second empty sequence of wave-vector filtering are frequently formula (14):

Wherein, R _d2(Ω) be the described second real sequence of wave-vector filtering frequently; I _d2(Ω) be the described second empty sequence of wave-vector filtering frequently; K (Ω) is for digital filtering is in the dimensionless gain of frequency difference Ω; α (Ω) for digital filtering is in the phase shift of frequency difference Ω, unit rad.

For step S109, preferably, integral operation formula can be (15):

Wherein, R ₂it is the second real vector product score value frequently; I ₂it is the second empty vector product score value frequently.L2 is second integral length, unit dimensionless, and in principle, L2 is minimum is 0.25 times of signal period sequence length.

For step S110, preferably, the phase place preset and amplitude transformation rule are with corresponding with the formula that the described first real vector product score value is frequently converted to first phase and sequence amplitude by the described first empty vector product score value frequently.

Preferably, by formula (16) and formula (17), the described first empty vector product score value frequently and the described first real vector product score value are frequently converted to first phase and sequence amplitude:

In formula, PH ₁for first phase, unit rad.

$Amp=\sqrt{{R_1}^2+{I_1}^2}=\frac{2AK\left(\mathrm{\Ω}\right)}{{\mathrm{\ΩT}}_{n}L1}sin\[\frac{{\mathrm{\ΩT}}_{n}L1}{2}\]---\left(17\right);$

In formula, Amp is sequence amplitude, unit v.

In one embodiment, according to the phase place preset and amplitude transformation rule, the step that the described first empty vector product score value frequently and the described first real vector product score value are frequently converted to first phase and sequence amplitude is comprised the following steps:

Obtain the ratio of the described first empty vector product score value frequently and the described first real vector product score value frequently.

Obtain the opposite number of the arctan function value of described ratio, generate described first phase.

Obtain the quadratic sum of the described first empty vector product score value frequently and the described first real vector product score value frequently.

Root is opened to the quadratic sum obtained, generates described sequence amplitude.

For step S111, preferably, the phase transition rule preset corresponds to empty vector product score value frequently and real vector is frequently converted to the change type of phase place.By following formula (18), the described second empty vector product score value frequently and the described second real vector product score value are frequently converted to second phase:

PH ₂for second phase, unit rad.

In one embodiment, according to described default phase transition rule, the step that the described second empty vector product score value frequently and the described second real vector product score value are frequently converted to second phase is comprised the following steps:

Obtain the ratio of the described second empty vector product score value frequently and the described second real vector product score value frequently;

Obtain the opposite number of the arctan function value of described ratio, generate described second phase.

For step S112, preferably, described default frequency difference transformation rule is corresponding to the change type described first phase and described second phase being converted to the frequency difference of described frequency power signal and described reference frequency.

According to formula (16) formula (18), the frequency difference calculating formula of described frequency power signal and described reference frequency can be formula (19):

$\mathrm{\Δ}\mathrm{\ω}=\frac{2({\mathrm{PH}}_1-{\mathrm{PH}}_2)}{(L1-L2)T_n}=\mathrm{\Ω}---\left(19\right);$

Wherein, △ ω is the frequency difference of described frequency power signal and described reference frequency, unit rad/s.

In one embodiment, according to the frequency difference transformation rule preset, the step that described first phase and described second phase are converted to the frequency difference of described frequency power signal and described reference frequency is comprised the following steps:

Obtain the integral and calculating length of the described first real sequence of wave-vector filtering frequently being carried out to integral operation, generate first integral length.

Obtain the integral and calculating length of the described second real sequence of wave-vector filtering frequently being carried out to integral operation, generate second integral length.

Obtain the difference of described first phase and described second phase, generate the first difference.

Obtain 2 times of the product of described first difference and described default sample frequency, generate the first product.

Obtain the difference of described first integral length and described second integral length, generate the second difference.

Obtain the ratio of described first product and described second difference, generate described frequency difference.

For step S113, preferably, described default amplitude transformation rule is corresponding to the change type frequency difference of described sequence amplitude and described frequency power signal and described reference frequency being converted to the amplitude of described electric power signal.The calculating formula of the amplitude of described electric power signal can be formula (20):

$AMP=\left|Amp\frac{{\mathrm{\Δ\ωT}}_{n}L1}{2\sin \[\frac{{\mathrm{\Δ\ωT}}_{n}L1}{2}\]}{\[\frac{{\mathrm{\Δ\ωT}}_n{N}_{D1}}{2sin\left(\frac{{\mathrm{\Δ\ωT}}_n{N}_{D1}}{2}\right)}\]}^3{\[\frac{{\mathrm{\Δ\ωT}}_n{N}_{D2}}{2sin\left(\frac{{\mathrm{\Δ\ωT}}_n{N}_{D2}}{2}\right)}\]}^3\right|=A---\left(20\right);$

Wherein, AMP is the fundamental voltage amplitude detected value of described electric power signal, unit v.

Refer to Fig. 2, Fig. 2 is the structural representation of amplitude detection system first embodiment of electric power signal of the present invention.

The amplitude detection system of the electric power signal described in present embodiment, sampling module 1010, preliminary survey module 1020, brachymemma module 1030, first frequency mixing module 1040, second frequency mixing module 1050, first filtration module 1060, first integral module 1070, second filtration module 1080, second integral module 1090, phase-amplitude modular converter 1100, phase conversion 1110, frequency difference modular converter 1120 and amplitude modular converter 1130 can be comprised, wherein:

Sampling module 1010, for calculating predetermined sequence length according to preset signals periodicity and default sample frequency, sampling to electric power signal, obtaining the burst of predetermined sequence length.

Preliminary survey module 1020, for carrying out frequency preliminary survey to described burst, generates the first synchronizing frequency of described electric power signal, with the described just given reference frequency of synchronizing frequency.

Brachymemma module 1030, for carrying out brachymemma process to described burst, obtain truncated signal sequence, the brachymemma value of the length of the relatively described burst of length of described truncated signal sequence is 0.25 times of signal period sequence length.

First frequency mixing module 1040, for being multiplied with described burst respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generates the first real sequence vector frequently and the first empty sequence vector frequently.

Second frequency mixing module 1050, for being multiplied with described truncated signal sequence respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generates the second real sequence vector frequently and the second empty sequence vector frequently.

First filtration module 1060, for carrying out digital filtering to the described first real sequence vector frequently and the described first empty sequence vector frequently respectively, generates the first real wave-vector filtering sequence frequently and the first empty sequence of wave-vector filtering frequently.

First integral module 1070, for carrying out integral operation to the described first real wave-vector filtering sequence frequently and the described first empty sequence of wave-vector filtering frequently respectively, generates the first real vector product score value frequently and the first empty vector product score value frequently.

Second filtration module 1080, for carrying out digital filtering to the described second real sequence vector frequently and the described second empty sequence vector frequently respectively, generates the second real wave-vector filtering sequence frequently and the second empty sequence of wave-vector filtering frequently.

Second integral module 1090, for carrying out integral operation to the described second real wave-vector filtering sequence frequently and the described second empty sequence of wave-vector filtering frequently respectively, generates the second real vector product score value frequently and the second empty vector product score value frequently.

Phase-amplitude modular converter 1100, for according to the phase place preset and amplitude transformation rule, is converted to first phase and sequence amplitude by the described first empty vector product score value frequently and the described first real vector product score value frequently.

Phase conversion 1110, for according to the phase transition rule preset, is converted to second phase by the described second empty vector product score value frequently and the described second real vector product score value frequently.

Frequency difference modular converter 1120, for according to the frequency difference transformation rule preset, is converted to the frequency difference of described frequency power signal and described reference frequency by described first phase and described second phase.

Amplitude modular converter 1130, for according to the amplitude transformation rule preset, is converted to the fundamental voltage amplitude of described electric power signal by the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency.

Present embodiment, carry out brachymemma process to the burst of sampling gained, obtain truncated signal sequence, the brachymemma value of the length of the relatively described burst of length of described truncated signal sequence is 0.25 times of signal period sequence length; With the cosine function of survey reference frequency be multiplied with described truncated signal sequence with described burst respectively with the sine function of described reference frequency, generate two groups of real sequence vectors frequently and empty sequence vectors frequently; By to two groups of empty sequence vectors frequently and real sequence vector digital filtering frequently, generate two groups of imaginary number wave-vector filtering sequences and real number wave-vector filtering sequence, and then integration generates two groups of imaginary number vector product score values and real number vector product score value; Again according to the phase transition rule preset, two groups of real number vector product score values and imaginary number vector product score value are converted to sequence amplitude and two phase places, according to the frequency difference transformation rule preset, be the frequency difference of described frequency power signal and described reference frequency by two phase transition; According to the amplitude transformation rule preset, the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency is converted to the amplitude of described electric power signal, there is higher accuracy.

Wherein, for sampling module 1010, preferably, described preset signals periodicity is set according to actual needs.Sample devices by electrical network field is sampled to described electric power signal, and described preset signals periodicity can be integer 11, because there is error, integer 11 is about.

Further, electric system rated frequency 50Hz, in order to improve performance, sample frequency much larger than 50Hz, should can arrange described default sample frequency f _n=10KHz, sampling interval is expressed as formula (1):

$T_n=\frac{1}{f_n}---\left(1\right);$

Wherein, T _nfor sampling interval, unit s; f _nfor described default sample frequency, unit Hz.

In one embodiment, described preset signals periodicity and described default sample frequency are converted to described predetermined sequence length by the following stated formula (2) by sampling module 1010:

N＝(int)C _2πT _2πf _n(2)；

Wherein, N is burst length, unit dimensionless; (int) be round numbers; C _{2 π}for preset signals periodicity, unit dimensionless; T _{2 π}for the signal period, unit s.

Actual in the described reference frequency calculating signal period, there is error.

Described burst, shown in Fig. 3.To single detection frequency signal, described burst is expressed as formula (3):

Wherein, X _in () is burst; A is signal fundamental voltage amplitude, unit v; ω is signal frequency, unit rad/s; T _nfor sampling interval, unit s; N is series of discrete number, unit dimensionless; for signal initial phase, unit rad, N are described predetermined sequence length, unit dimensionless.

For preliminary survey module 1020, by zero friendship method, frequency preliminary survey is carried out to described burst, obtain described just synchronizing frequency.Also by other frequency measurement methods that those skilled in the art are usual, frequency preliminary survey is carried out to described input signal sequence.

Described preliminary frequency is expressed as formula (4):

ω _o(4)；

Wherein, ω _ofor first synchronizing frequency, unit rad/s;

Preferably, described reference frequency is expressed as formula (5):

ω _s＝ω _o(5)；

Wherein, ω _sfor reference frequency, unit rad/s; ω _ofor first synchronizing frequency, unit rad/s.

For brachymemma module 1030, preferably, described truncated signal sequence length is expressed as formula (6):

N _S＝N-0.25N _2π(6)；

In formula, N _sfor truncated signal sequence length, unit dimensionless; N _{2 π}for signal unit periodic sequence length, unit dimensionless.

Preferably, calculate signal unit periodic sequence length according to described reference frequency, be formula (7):

$N_{2\mathrm{\π}}=\left(\mathrm{int}\right)\frac{2\mathrm{\π}}{{\mathrm{\ω}}_s{T}_n}---\left(7\right);$

Wherein, (int) represents round numbers process, signal unit periodic sequence length N _{2 π}there is the error in 1 sampling interval in integer.

Described truncated signal sequence, shown in Fig. 3.Described truncated signal sequence is expressed as formula (8):

In formula, X ₂n () is truncated signal sequence.

For the first frequency mixing module 1040, preferably, the cosine function of described reference frequency and the sine function of described reference frequency can be respectively with described reference frequency be frequency, with T _nfor sine function and the cosine function of spaced discrete variable.

In one embodiment, be multiplied with described burst respectively with the sine function of described reference frequency with the cosine function of described reference frequency, obtain described first real sequence vector frequently and the described first empty sequence vector is frequently formula (9):

Wherein, R ₁n () is the described first real sequence vector frequently; I ₁n () is the described first empty sequence vector frequently; Ω is the frequency difference of signal frequency and reference frequency, unit with for active constituent; with for mixing interfering frequency composition.

For the second frequency mixing module 1050, be multiplied with described truncated signal sequence respectively with the sine function of described reference frequency with the cosine function of described reference frequency, obtain described second real sequence vector frequently and the described second empty sequence vector is frequently formula (10):

In formula, R ₂n () is the described second real sequence vector frequently; I ₂n () is the described second empty sequence vector frequently; Ω is the frequency difference of signal frequency and reference frequency, unit rad/s; with for active constituent; with for mixing interfering frequency composition.

For the first filtration module 1060, in the described first real sequence vector frequently and the described first empty sequence vector frequently, comprise mixing interfering frequency.When in input signal also at flip-flop, subharmonic composition and subharmonic composition time, described mixing interfering frequency will be more complicated, and these mixing interfering frequencies have a strong impact on accuracy in computation.Although window function and integral operation itself have good attenuation to mixing interfering frequency, do not have specific aim, can not produce the inhibiting effect of the degree of depth to the mixing interfering frequency of described complexity, the pin-point accuracy that can not meet parameter calculates needs.

In order to suppress the impact of described mixing interfering frequency targetedly, adopt a kind of digital filter, ideally, the null Frequency point just in time corresponding described mixing interfering frequency point of digital filter, has inhibiting effect completely to described mixing interfering frequency.Preferably, digital filtering specifically adopts digital averaging filtering algorithm, is added, then gets its arithmetic mean and export as this filter value by several continuous discrete values.Digital filtering needs to arrange digital filter parameters, and described digital filter parameters refers to the length N that several continuous discrete values are added _d.At digital filter parameters N _dvalue is 1.5 times of signal period sequence length, can suppress the mixing interfering frequency that 1/3 subharmonic produces.And N _dvalue is 2 times of signal period sequence length, can to direct current, 1/2 gradation, 1 time, 2 times, 3 times, 4 times, the mixing interfering frequency that produces such as 5 subharmonic suppresses.Therefore, digital filtering is made up of the digital filter of 2 kinds of parameters, considers the factors such as physical presence error, in order to the degree of depth suppresses the impact of mixing interfering frequency, the digital filter of often kind of parameter forms by the three stages of digital filtering that parameter is identical, and totally six grades of arithmetic mean digital filterings formed.

Preferably, six grades of arithmetic mean digital filtering formulas can be formula (11):

Wherein, X (n) is digital filtering list entries, sequence length N; X _dn () is digital filtering output sequence, sequence length N-3N _d1-3N _d2; N _d1for filtering parameter 1, namely discrete value is added quantity continuously; N _d2for filtering parameter 2, namely discrete value is added quantity continuously.

In one embodiment, filtering parameter N _d1value is 1.5 times of the unit period sequence length of described reference frequency, filtering parameter N _d2value is 2 times of the unit period sequence length of described reference frequency, and six grades of arithmetic mean digital filterings need use 10.5 times of signal period sequence lengths.

Preferably, under described mixing interfering frequency composition is suppressed prerequisite completely, the described first real wave-vector filtering sequence frequently and the described first empty sequence of wave-vector filtering are frequently (12):

Wherein, R _d1(Ω) be the described first real sequence of wave-vector filtering frequently; I _d1(Ω) be the described first empty sequence of wave-vector filtering frequently; K (Ω) is for digital filtering is in the dimensionless gain of frequency difference Ω; α (Ω) for digital filtering is in the phase shift of frequency difference Ω, unit rad.

For first integral module 1070, preferably, integral operation formula is (13):

Wherein, R ₁it is the first real vector product score value frequently; I ₁it is the first empty vector product score value frequently.L1 is first integral length, unit dimensionless, and in principle, L1 is minimum is 0.5 times of signal period sequence length.

For the second filtration module 1080, in like manner and preferably, under described mixing interfering frequency composition is suppressed prerequisite completely, the described second real wave-vector filtering sequence frequently and the described second empty sequence of wave-vector filtering are frequently formula (14):

Wherein, R _d2(Ω) be the described second real sequence of wave-vector filtering frequently; I _d2(Ω) be the described second empty sequence of wave-vector filtering frequently; K (Ω) is for digital filtering is in the dimensionless gain of frequency difference Ω; α (Ω) for digital filtering is in the phase shift of frequency difference Ω, unit rad.

For second integral module 1090, preferably, integral operation formula can be (15):

Wherein, R ₂it is the second real vector product score value frequently; I ₂it is the second empty vector product score value frequently.L2 is second integral length, unit dimensionless, and in principle, L2 is minimum is 0.25 times of signal period sequence length.

For phase-amplitude modular converter 1100, preferably, the phase place preset and amplitude transformation rule are with corresponding with the formula that the described first real vector product score value is frequently converted to first phase and sequence amplitude by the described first empty vector product score value frequently.

Preferably, the described first empty vector product score value frequently and the described first real vector product score value are frequently converted to first phase and sequence amplitude by formula (16) and formula (17) by phase-amplitude modular converter 1100:

In formula, PH ₁for first phase, unit rad.

$Amp=\sqrt{{R_1}^2+{I_1}^2}=\frac{2AK\left(\mathrm{\Ω}\right)}{{\mathrm{\ΩT}}_{n}L1}sin\[\frac{{\mathrm{\ΩT}}_{n}L1}{2}\]---\left(17\right);$

In formula, Amp is sequence amplitude, unit v.

In one embodiment, phase-amplitude modular converter 1100 also can be used for:

Obtain the ratio of the described first empty vector product score value frequently and the described first real vector product score value frequently.

Obtain the opposite number of the arctan function value of described ratio, generate described first phase.

Obtain the quadratic sum of the described first empty vector product score value frequently and the described first real vector product score value frequently.

Root is opened to the quadratic sum obtained, generates described sequence amplitude.

For phase conversion 1110, preferably, the phase transition rule preset corresponds to empty vector product score value frequently and real vector is frequently converted to the change type of phase place.By following formula (18), the described second empty vector product score value frequently and the described second real vector product score value are frequently converted to second phase:

PH ₂for second phase, unit rad.

In one embodiment, phase conversion 1110 also can be used for:

Obtain the ratio of the described second empty vector product score value frequently and the described second real vector product score value frequently;

Obtain the opposite number of the arctan function value of described ratio, generate described second phase.

For frequency difference modular converter 1120, preferably, described default frequency difference transformation rule is corresponding to the change type described first phase and described second phase being converted to the frequency difference of described frequency power signal and described reference frequency.

According to formula (16) formula (18), the frequency difference calculating formula of described frequency power signal and described reference frequency can be formula (19):

$\mathrm{\Δ}\mathrm{\ω}=\frac{2({\mathrm{PH}}_1-{\mathrm{PH}}_2)}{(L1-L2)T_n}=\mathrm{\Ω}---\left(19\right);$

Wherein, Δ ω is the frequency difference of described frequency power signal and described reference frequency, unit rad/s.

In one embodiment, frequency difference modular converter 1120 can be used for:

Obtain the integral and calculating length of the described first real sequence of wave-vector filtering frequently being carried out to integral operation, generate first integral length.

Obtain the integral and calculating length of the described second real sequence of wave-vector filtering frequently being carried out to integral operation, generate second integral length.

Obtain the difference of described first phase and described second phase, generate the first difference.

Obtain 2 times of the product of described first difference and described default sample frequency, generate the first product.

Obtain the difference of described first integral length and described second integral length, generate the second difference.

Obtain the ratio of described first product and described second difference, generate described frequency difference.

For amplitude modular converter 1130, preferably, described default amplitude transformation rule is corresponding to the change type frequency difference of described sequence amplitude and described frequency power signal and described reference frequency being converted to the amplitude of described electric power signal.The calculating formula of the amplitude of described electric power signal can be formula (20):

$AMP=\left|Amp\frac{{\mathrm{\Δ\ωT}}_{n}L1}{2\sin \[\frac{{\mathrm{\Δ\ωT}}_{n}L1}{2}\]}{\[\frac{{\mathrm{\Δ\ωT}}_n{N}_{D1}}{2sin\left(\frac{{\mathrm{\Δ\ωT}}_n{N}_{D1}}{2}\right)}\]}^3{\[\frac{{\mathrm{\Δ\ωT}}_n{N}_{D2}}{2sin\left(\frac{{\mathrm{\Δ\ωT}}_n{N}_{D2}}{2}\right)}\]}^3\right|=A---\left(20\right);$

Wherein, AMP is the fundamental voltage amplitude detected value of described electric power signal, unit v.

In order to verify that the amplitude detection system of electric power signal of the present invention has higher accuracy, providing an experimental signal, being formula (21):

In experimental signal fundamental frequency variation range at 45Hz-55Hz, the number of winning the confidence integer multiples issue is about 11, signal initial phase variation range is at 0 ~ ± pi/2, unit rad, the sample frequency of signal is 10kHz, the discrete data quantization digit 24bit of signal, frequency preliminary survey relative error <| ± 0.25%|, obtains the absolute relative error that signal fundamental voltage amplitude detects | AMP _err(f) | with the experimental result picture of signal fundamental frequency f variation characteristic, shown in Fig. 4.The amplitude detection accuracy of the experimental signal that Fig. 4 provides is 10 ^-7magnitude.

Each technical characteristic of the above embodiment can combine arbitrarily, for making description succinct, the all possible combination of each technical characteristic in above-described embodiment is not all described, but, as long as the combination of these technical characteristics does not exist contradiction, be all considered to be the scope that this instructions is recorded.

The above embodiment only have expressed several embodiment of the present invention, and it describes comparatively concrete and detailed, but can not therefore be construed as limiting the scope of the patent.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.

Claims (10)

1. an amplitude detection method for electric power signal, is characterized in that, comprise the following steps:

Calculate predetermined sequence length according to preset signals periodicity and default sample frequency, electric power signal is sampled, obtain the burst of predetermined sequence length;

Frequency preliminary survey is carried out to described burst, generates the first synchronizing frequency of described electric power signal, and with described just synchronizing frequency for reference frequency;

Carry out brachymemma process to described burst, obtain truncated signal sequence, the brachymemma value of the sequence length of the relatively described burst of sequence length of described truncated signal sequence is 0.25 times of 1 periodic sequence length of described burst;

Be multiplied with described burst respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generate the first real sequence vector frequently and the first empty sequence vector frequently;

Be multiplied with described truncated signal sequence respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generate the second real sequence vector frequently and the second empty sequence vector frequently;

Respectively digital filtering is carried out to the described first real sequence vector frequently and the described first empty sequence vector frequently, generate the first real wave-vector filtering sequence frequently and the first empty sequence of wave-vector filtering frequently;

Respectively integral operation is carried out to the described first real wave-vector filtering sequence frequently and the described first empty sequence of wave-vector filtering frequently, generate the first real vector product score value frequently and the first empty vector product score value frequently;

Respectively digital filtering is carried out to the described second real sequence vector frequently and the described second empty sequence vector frequently, generate the second real wave-vector filtering sequence frequently and the second empty sequence of wave-vector filtering frequently;

Respectively integral operation is carried out to the described second real wave-vector filtering sequence frequently and the described second empty sequence of wave-vector filtering frequently, generate the second real vector product score value frequently and the second empty vector product score value frequently;

According to the phase place preset and amplitude transformation rule, the described first empty vector product score value frequently and the described first real vector product score value are frequently converted to first phase and sequence amplitude;

According to the phase transition rule preset, the described second empty vector product score value frequently and the described second real vector product score value are frequently converted to second phase;

According to the frequency difference transformation rule preset, described first phase and described second phase are converted to the frequency difference of described frequency power signal and described reference frequency;

According to the amplitude transformation rule preset, the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency is converted to the fundamental voltage amplitude of described electric power signal.

2. the amplitude detection method of electric power signal according to claim 1, is characterized in that, the step calculating predetermined sequence length according to preset signals periodicity and default sample frequency comprises the following steps:

By the following stated formula, described preset signals periodicity and described default sample frequency are converted to described predetermined sequence length:

N＝(int)C _2πT _2πf _n；

Wherein, N is described predetermined sequence length, unit dimensionless, and (int) expression rounds, C _{2 π}for described preset signals periodicity, unit dimensionless, T _{2 π}for the signal period, unit s, f _nfor described default sample frequency, unit Hz.

3. the amplitude detection method of electric power signal according to claim 1, is characterized in that, it is characterized in that, described digital filtering is made up of six grades of arithmetic mean digital filters.

4. the amplitude detection method of electric power signal according to claim 1, it is characterized in that, according to the phase place preset and amplitude transformation rule, the step that the described first empty vector product score value frequently and the described first real vector product score value are frequently converted to first phase and sequence amplitude is comprised the following steps:

Obtain the ratio of the described first empty vector product score value frequently and the described first real vector product score value frequently;

Obtain the opposite number of the arctan function value of described ratio, generate described first phase;

Obtain the quadratic sum of the described first empty vector product score value frequently and the described first real vector product score value frequently;

Root is opened to the quadratic sum obtained, generates described sequence amplitude.

5. the amplitude detection method of electric power signal as claimed in any of claims 1 to 4, it is characterized in that, according to the frequency difference transformation rule preset, the step that described first phase and described second phase are converted to the frequency difference of described frequency power signal and described reference frequency is comprised the following steps:

Obtain the integral and calculating length of the described first real sequence of wave-vector filtering frequently being carried out to integral operation, generate first integral length;

Obtain the integral and calculating length of the described second real sequence of wave-vector filtering frequently being carried out to integral operation, generate second integral length;

Obtain the difference of described first phase and described second phase, generate the first difference;

Obtain 2 times of the product of described first difference and described default sample frequency, generate the first product;

Obtain the difference of described first integral length and described second integral length, generate the second difference;

Obtain the ratio of described first product and described second difference, generate described frequency difference.

6. an amplitude detection system for electric power signal, is characterized in that, comprising:

Sampling module, for calculating predetermined sequence length according to preset signals periodicity and default sample frequency, sampling to electric power signal, obtaining the burst of predetermined sequence length;

Preliminary survey module, for carrying out frequency preliminary survey to described burst, generates the first synchronizing frequency of described electric power signal, and with described just synchronizing frequency for reference frequency;

Brachymemma module, for carrying out brachymemma process to described burst, obtain truncated signal sequence, the brachymemma value of the sequence length of the relatively described burst of sequence length of described truncated signal sequence is 0.25 times of 1 periodic sequence length of described burst;

First frequency mixing module, for being multiplied with described burst respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generates the first real sequence vector frequently and the first empty sequence vector frequently;

Second frequency mixing module, for being multiplied with described truncated signal sequence respectively with the sine function of described reference frequency with the cosine function of described reference frequency, generates the second real sequence vector frequently and the second empty sequence vector frequently;

First filtration module, for carrying out digital filtering to the described first real sequence vector frequently and the described first empty sequence vector frequently respectively, generates the first real wave-vector filtering sequence frequently and the first empty sequence of wave-vector filtering frequently;

First integral module, for carrying out integral operation to the described first real wave-vector filtering sequence frequently and the described first empty sequence of wave-vector filtering frequently respectively, generates the first real vector product score value frequently and the first empty vector product score value frequently;

Second filtration module, for carrying out digital filtering to the described second real sequence vector frequently and the described second empty sequence vector frequently respectively, generates the second real wave-vector filtering sequence frequently and the second empty sequence of wave-vector filtering frequently;

Second integral module, for carrying out integral operation to the described second real wave-vector filtering sequence frequently and the described second empty sequence of wave-vector filtering frequently respectively, generates the second real vector product score value frequently and the second empty vector product score value frequently;

Phase-amplitude modular converter, for according to the phase place preset and amplitude transformation rule, is converted to first phase and sequence amplitude by the described first empty vector product score value frequently and the described first real vector product score value frequently;

Phase conversion, for according to the phase transition rule preset, is converted to second phase by the described second empty vector product score value frequently and the described second real vector product score value frequently;

Frequency difference modular converter, for according to the frequency difference transformation rule preset, is converted to the frequency difference of described frequency power signal and described reference frequency by described first phase and described second phase;

Amplitude modular converter, for according to the amplitude transformation rule preset, is converted to the fundamental voltage amplitude of described electric power signal by the frequency difference of described sequence amplitude, described frequency power signal and described reference frequency.

7. the amplitude detection system of electric power signal according to claim 6, is characterized in that, described sampling module is also for being converted to described predetermined sequence length by the following stated formula by described preset signals periodicity and described default sample frequency:

N＝(int)C _2πT _2πf _n；

Wherein, N is described predetermined sequence length, unit dimensionless, and (int) expression rounds, C _{2 π}for described preset signals periodicity, unit dimensionless, T _{2 π}for the signal period, unit s, f _nfor described default sample frequency, unit Hz.

8. the amplitude detection system of electric power signal according to claim 6, is characterized in that, described digital filtering is made up of six grades of arithmetic mean digital filters.

9. the amplitude detection system of electric power signal according to claim 6, is characterized in that, described phase-amplitude modular converter also for:

Obtain the ratio of the described first empty vector product score value frequently and the described first real vector product score value frequently;

Obtain the opposite number of the arctan function value of described ratio, generate described first phase;

Obtain the quadratic sum of the described first empty vector product score value frequently and the described first real vector product score value frequently;

Root is opened to the quadratic sum obtained, generates described sequence amplitude.

10., according to the amplitude detection system of the electric power signal in claim 6 to 9 described in any one, it is characterized in that, described frequency difference modular converter also for:

Obtain the integral and calculating length of the described first real sequence of wave-vector filtering frequently being carried out to integral operation, generate first integral length;

Obtain the integral and calculating length of the described second real sequence of wave-vector filtering frequently being carried out to integral operation, generate second integral length;

Obtain the difference of described first phase and described second phase, generate the first difference;

Obtain 2 times of the product of described first difference and described default sample frequency, generate the first product;

Obtain the difference of described first integral length and described second integral length, generate the second difference;

Obtain the ratio of described first product and described second difference, generate described frequency difference.