CN105301356A - Method and system of obtaining zero initial phase reference cosine function frequency multiplication sequence - Google Patents
Method and system of obtaining zero initial phase reference cosine function frequency multiplication sequence Download PDFInfo
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Abstract
The invention relates to a method and system of obtaining a zero initial phase reference cosine function frequency multiplication sequence, comprising: through a series of operations, obtaining a cosine function modulation sequence and a sine function modulation sequence; performing outputting from the central point of the cosine function modulation sequence to obtain a zero initial phase reference cosine function modulation sequence; performing outputting from the central point of the sine function modulation sequence to obtain a zero initial phase reference sine function modulation sequence; and obtaining a zero initial phase reference cosine function frequency multiplication sequence according to the zero initial phase reference cosine function modulation sequence and the zero initial phase reference sine function modulation sequence. The zero initial phase reference cosine function frequency multiplication sequence can be applied to the measurement of electric power signal frequencies, thereby substantially improving the accuracy of electric power signal frequency measurement.
Description
Technical field
The present invention relates to technical field of power systems, particularly relate to the method and system of a kind of acquisition zero initial phase benchmark cosine function times frequency sequence.
Background technology
The frequency measurement, phase measurement, amplitude measurement etc. of electric system are the measurement of sine parameter in itself.Fourier transform is the basic skills realizing sine parameter measurement, is widely used in electric system.But along with the development of sine parameter measuring technique, Fourier transform Problems existing is also more aobvious outstanding, and it is difficult to the requirement meeting the calculating of electric system offset of sinusoidal parameter pin-point accuracy further.
In the measurement of electric system sine parameter, also has the measurement method of parameters that some improve, as zero hands over method, based on the mensuration of filtering, based on Wavelet Transform, the mensuration based on neural network, the mensuration etc. that converts based on DFT (DiscreteFourierTransform, discrete Fourier transformation).Because the specified power frequency of operation of power networks is near 50Hz (hertz), belong to the sinusoidal frequency that frequency is lower, and interference is there is in the electric power signal of reality, such as humorous wave interference, electric load among a small circle in random fluctuation produce similar white noise interference etc., under interference environment, the problem that the ubiquitous accuracy of measurement of these algorithms is not high.
Summary of the invention
Based on this, be necessary for the problems referred to above, the method and system of a kind of acquisition zero initial phase benchmark cosine function times frequency sequence is provided, the accuracy that frequency power signal is measured can be improved.
For solving the problems of the technologies described above, the present invention adopts following technical scheme:
Obtain a method for zero initial phase benchmark cosine function times frequency sequence, comprise step:
According to the lower limit of frequency power signal scope, default sample frequency and default integer signal period number, obtain preliminary sequence length;
According to described preliminary sequence length, electric power signal is sampled, obtain the preliminary sequence of described electric power signal;
Frequency preliminary survey is carried out to described preliminary sequence, obtains the first synchronizing frequency of described electric power signal, obtain reference frequency according to described just synchronizing frequency;
According to described default sample frequency and described reference frequency, obtain the unit period sequence length of described electric power signal;
Described default integer signal period number is multiplied with described unit period sequence length, obtains preprocessing sequence length;
According to described preprocessing sequence length, from the preliminary sequence of described electric power signal, obtain preprocessing sequence;
Carry out comb filtering process to described preprocessing sequence, obtain comb filtering sequence, wherein comb filtering sequence length is the residue length of described preprocessing sequence after carrying out comb filtering process;
Determine the ratio integer of described comb filtering sequence length and described unit period sequence length, obtain predetermined sequence length according to described ratio integer and described unit period sequence length, wherein said ratio integer is odd number, and described predetermined sequence length is odd number;
According to described predetermined sequence length and default starting point, from described comb filtering sequence, obtain the first forward sequence, obtain the first anti-pleat sequence according to described first forward sequence;
Obtain the first positive phase according to described first forward sequence, obtain the first antiphase according to described first anti-pleat sequence;
The first average initial phase is obtained according to described first positive phase and described first antiphase;
According to the described first average initial phase and preset phase value, obtain phase compare value, according to described phase compare value, described default starting point and described unit period sequence length, obtain new starting point;
According to described predetermined sequence length and described new starting point, from described comb filtering sequence, obtain the second forward sequence, obtain the second anti-pleat sequence according to the second forward sequence;
Obtain the second positive phase according to described second forward sequence, obtain the second antiphase according to described second anti-pleat sequence;
The second average initial phase is obtained according to described second positive phase and described second antiphase;
Described second forward sequence is added with described second anti-pleat sequence, obtains and sequence, according to described and sequence and the described second average initial phase cosine function value, obtain cosine function modulation sequence;
Described second forward sequence and described second anti-pleat sequence are subtracted each other, obtains difference sequence, according to the sine function of described difference sequence and the described second average initial phase, obtain sine function modulation sequence;
Export from described cosine function modulation sequence central point, obtain zero initial phase benchmark cosine function modulation sequence, export from described sine function modulation sequence central point, obtain zero initial phase reference sinusoidal FUNCTION MODULATION sequence;
By described zero initial phase benchmark cosine function modulation sequence square with square the subtracting each other of described zero initial phase reference sinusoidal FUNCTION MODULATION sequence, obtain zero initial phase benchmark cosine function times frequency sequence.
Obtain a system for zero initial phase benchmark cosine function times frequency sequence, comprising:
Preliminary sequence length determination modul, for the lower limit according to frequency power signal scope, presets sample frequency and default integer signal period number, obtains preliminary sequence length;
Preliminary sequence acquisition module, for sampling to electric power signal according to described preliminary sequence length, obtains the preliminary sequence of described electric power signal;
Reference frequency determination module, for carrying out frequency preliminary survey to described preliminary sequence, obtains the first synchronizing frequency of described electric power signal, obtains reference frequency according to described just synchronizing frequency;
Unit period sequence length determination module, for according to described default sample frequency and described reference frequency, obtains the unit period sequence length of described electric power signal;
Preprocessing sequence length determination modul, for being multiplied with described unit period sequence length by described default integer signal period number, obtains preprocessing sequence length;
Preprocessing sequence acquisition module, for according to described preprocessing sequence length, obtains preprocessing sequence from the preliminary sequence of described electric power signal;
Comb filtering sequence determination module, for carrying out comb filtering process to described preprocessing sequence, obtain comb filtering sequence, wherein comb filtering sequence length is the residue length of described preprocessing sequence after carrying out comb filtering process;
Predetermined sequence length determination modul, for determining the ratio integer of described comb filtering sequence length and described unit period sequence length, predetermined sequence length is obtained according to described ratio integer and described unit period sequence length, wherein said ratio integer is odd number, and described predetermined sequence length is odd number;
First ray acquisition module, for according to described predetermined sequence length and default starting point, obtains the first forward sequence from described comb filtering sequence, obtains the first anti-pleat sequence according to described first forward sequence;
First positive and negative phase determination module, for obtaining the first positive phase according to described first forward sequence, obtains the first antiphase according to described first anti-pleat sequence;
First average initial phase determination module, for obtaining the first average initial phase according to described first positive phase and described first antiphase;
New starting point determination module, for according to the described first average initial phase and preset phase value, obtains phase compare value, according to described phase compare value, described default starting point and described unit period sequence length, obtains new starting point;
Second retrieval module, for according to described predetermined sequence length and described new starting point, obtains the second forward sequence from described comb filtering sequence, obtains the second anti-pleat sequence according to the second forward sequence;
Second positive and negative phase determination module, for obtaining the second positive phase according to described second forward sequence, obtains the second antiphase according to described second anti-pleat sequence;
Second average initial phase determination module, for obtaining the second average initial phase according to described second positive phase and described second antiphase;
Cosine function modulation sequence determination module, for described second forward sequence being added with described second anti-pleat sequence, obtains and sequence, according to described and sequence and the described second average initial phase cosine function value, obtains cosine function modulation sequence;
Sine function modulation sequence determination module, for described second forward sequence and described second anti-pleat sequence being subtracted each other, obtains difference sequence, according to the sine function of described difference sequence and the described second average initial phase, obtains sine function modulation sequence;
Zero initial phase modulation sequence acquisition module, for exporting from described cosine function modulation sequence central point, obtain zero initial phase benchmark cosine function modulation sequence, export from described sine function modulation sequence central point, obtain zero initial phase reference sinusoidal FUNCTION MODULATION sequence;
Zero initial phase benchmark cosine function times frequency sequence determination module, for by described zero initial phase benchmark cosine function modulation sequence square with square the subtracting each other of described zero initial phase reference sinusoidal FUNCTION MODULATION sequence, obtain zero initial phase benchmark cosine function times frequency sequence.
The present invention obtains the method and system of zero initial phase benchmark cosine function times frequency sequence, carries out process of frequency multiplication to the frequency of input electric power burst, obtains zero initial phase benchmark cosine function times frequency sequence.The zero initial phase benchmark cosine function times frequency sequence that the present invention obtains is used for the measurement of frequency power signal, the accuracy that frequency power signal is measured can be significantly improved.
Accompanying drawing explanation
Fig. 1 is the schematic flow sheet that the present invention obtains the embodiment of the method for zero initial phase benchmark cosine function times frequency sequence;
Fig. 2 is the schematic diagram of comb filtering process of the present invention in frequency domain amplitude versus frequency characte;
Fig. 3 is the schematic diagram of preliminary sequence of the present invention, the first forward sequence and the first anti-pleat sequence;
Fig. 4 is the pictorial diagram of the present invention zero initial phase reference point;
Fig. 5 is the structural representation that the present invention obtains the system embodiment of zero initial phase benchmark cosine function times frequency sequence.
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.
As shown in Figure 1, the method for a kind of acquisition zero initial phase benchmark cosine function times frequency sequence, comprises step:
S101, the lower limit according to frequency power signal scope, default sample frequency and default integer signal period number, obtain preliminary sequence length;
S102, according to described preliminary sequence length, electric power signal to be sampled, obtain the preliminary sequence of described electric power signal;
S103, frequency preliminary survey is carried out to described preliminary sequence, obtain the first synchronizing frequency of described electric power signal, obtain reference frequency according to described just synchronizing frequency;
S104, according to described default sample frequency and described reference frequency, obtain the unit period sequence length of described electric power signal;
S105, described default integer signal period number to be multiplied with described unit period sequence length, to obtain preprocessing sequence length;
S106, according to described preprocessing sequence length, from the preliminary sequence of described electric power signal, obtain preprocessing sequence;
S107, carry out comb filtering process to described preprocessing sequence, obtain comb filtering sequence, wherein comb filtering sequence length is the residue length of described preprocessing sequence after carrying out comb filtering process;
S108, determine the ratio integer of described comb filtering sequence length and described unit period sequence length, predetermined sequence length is obtained according to described ratio integer and described unit period sequence length, wherein said ratio integer is odd number, and described predetermined sequence length is odd number;
S109, according to described predetermined sequence length and default starting point, from described comb filtering sequence, obtain the first forward sequence, obtain the first anti-pleat sequence according to described first forward sequence;
S110, obtain the first positive phase according to described first forward sequence, obtain the first antiphase according to described first anti-pleat sequence;
S111, according to described first positive phase and described first antiphase obtain the first average initial phase;
S112, according to the described first average initial phase and preset phase value, obtain phase compare value, according to described phase compare value, described default starting point and described unit period sequence length, obtain new starting point;
S113, according to described predetermined sequence length and described new starting point, from described comb filtering sequence, obtain the second forward sequence, obtain the second anti-pleat sequence according to the second forward sequence;
S114, obtain the second positive phase according to described second forward sequence, obtain the second antiphase according to described second anti-pleat sequence;
S115, according to described second positive phase and described second antiphase obtain the second average initial phase;
S116, described second forward sequence to be added with described second anti-pleat sequence, to obtain and sequence, according to described and sequence and the described second average initial phase cosine function value, acquisition cosine function modulation sequence;
S117, described second forward sequence and described second anti-pleat sequence to be subtracted each other, obtain difference sequence, according to the sine function of described difference sequence and the described second average initial phase, obtain sine function modulation sequence;
S118, to export from described cosine function modulation sequence central point, obtain zero initial phase benchmark cosine function modulation sequence, export from described sine function modulation sequence central point, obtain zero initial phase reference sinusoidal FUNCTION MODULATION sequence;
S119, by described zero initial phase benchmark cosine function modulation sequence square with square the subtracting each other of described zero initial phase reference sinusoidal FUNCTION MODULATION sequence, obtain zero initial phase benchmark cosine function times frequency sequence.
Actual electrical force signal is a kind of based on the sinusoidal signal of first-harmonic composition, and if no special instructions, electric power signal all refers to fundamental signal, and frequency power signal all refers to fundamental frequency.For step S101, power system frequency scope is generally at 45Hz (hertz)-55Hz, so the lower limit f of frequency power signal scope
min45Hz can be taken as.Preset integer signal period number C
2 πcan arrange according to actual needs, such as, by C
2 πbe taken as 17.Preliminary sequence length can calculate according to formula (1):
Wherein, N
startfor preliminary sequence length; (int) expression rounds; C
2 πfor default integer signal period number; f
minfor the lower limit of frequency power signal scope, unit Hz; F is for presetting sample frequency, unit Hz.
For step S102, can with the cosine function signal representation electric power signal of single fundamental frequency, so preliminary sequence is formula (2):
n=0,1,2,3,.....,N
start-1
Wherein, X
startn () is preliminary sequence; A is signal amplitude, unit v; ω
ifor signal frequency, T is sampling interval duration, and f is for presetting sample frequency, and unit Hz, n are series of discrete number,
for the initial phase of preliminary sequence, N
startfor preliminary sequence length.
For step S103, by zero friendship method, based on filtering algorithm, based on Wavelet Transformation Algorithm, based on neural network algorithm, based on DFT conversion frequency algorithm or based on the frequency algorithm of phase differential, frequency preliminary survey is carried out to preliminary sequence, obtain preliminary frequencies omega
o.In one embodiment, described reference frequency ω
s=ω
o.
For step S104, in one embodiment, the unit period sequence length of described electric power signal calculates, and is formula (3):
Wherein, N
2 πfor unit periodic sequence length; (int) be round numbers; F is for presetting sample frequency, unit Hz; ω
sfor reference frequency.There is the error in 1 sampling interval in described unit period sequence length integer.
For step S105, described preprocessing sequence length is formula (4):
N
set=C
2πN
2π(4)
Wherein, N
setfor preprocessing sequence length; C
2 πfor default integer signal period number; N
2 πfor unit periodic sequence length.
For step S106, in one embodiment, obtain preprocessing sequence, be formula (5):
(5)
n=0,1,2,3,.....,N
set-1
Wherein, X
setn () is preprocessing sequence, X
startn () is preliminary sequence, N
setfor preprocessing sequence length.
There are subharmonic, even-order harmonic, odd harmonic etc. in electric power signal, in described frequency multiplication process, the mixing frequencies of subharmonic and even-order harmonic will be superimposed upon near first-harmonic frequency multiplication frequency, have a strong impact on the quality of first-harmonic frequency-doubled signal.And can suppressing the even-order harmonic in electric power signal and decaying subharmonic of comb filtering process, effectively can improve the quality of first-harmonic frequency-doubled signal.
For step S107, list entries different for 2 starting points is subtracted each other, the frequency domain amplitude-frequency filtering characteristic of pectination can be obtained, referred to as comb filtering process.The interval of 2 list entries is defined as comb filtering parameter, and the process of single-stage comb filtering is expressed as formula (6):
n=0,1,2,3,.......,N
set-N
L-1(6)
N
L=(int)(0.5N
2π)
Wherein, X
ln () is single-stage comb filtering output sequence; X
setn () is preprocessing sequence; X
set(N
l+ n) be from N
linitial preprocessing sequence; N
lbe 2 train interval or single-stage comb filtering parameter; N
setfor preprocessing sequence length; N
2 πfor unit periodic sequence length.Comb filtering Parameter N
lvalue is unit periodic sequence length N
2 π0.5 times, can suppress even-order harmonic and subharmonic be decayed.
In one embodiment, comb filtering process can be carried out by comb filter to described preprocessing sequence.Due to reference frequency there is error, there is integer error in comb filtering parameter, in order to improve comb-filter effects, comb filtering process can be carried out by 8 grades of comb filter, being expressed as formula (7):
X
8L(n):n=0,1,2,3,.....,N
set-8N
L-1(7)
X
set(n):n=0,1,2,3,.....,N
set-1
N
L=(int)(0.5N
2π)
Wherein, X
8Ln () is 8 grades of comb filter or comb filtering sequence; Filter [8, NL, X
set(n)] in 8 to represent comb filtering progression be 8, N
lfor single-stage comb filtering parameter, X
setn () is preprocessing sequence; K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain, T is sampling interval duration;
for comb filtering sequence initial phase; N
setfor preprocessing sequence length.
Comb filtering process needs applying unit periodic sequence length N
2 π4 times of sequence lengths.Comb filtering process in frequency domain amplitude versus frequency characte as shown in Figure 2.
For step S108, in one embodiment, ratio integer is set to odd number, determines the ratio integer of described comb filtering sequence length and described unit period sequence length, is formula (8):
Wherein, k is described ratio integer, N
setfor preprocessing sequence length, N
lfor single-stage comb filtering parameter, N
2 πfor unit periodic sequence length.
In one embodiment, predetermined sequence length is set to odd number, and predetermined sequence length computation is formula (9):
Wherein, N is predetermined sequence length, and k is described ratio integer, N
2 πfor unit periodic sequence length.
For step S109, in one embodiment, default starting point can be 0.5 times of described unit period sequence length, and described first forward sequence is formula (10):
P
start=(int)(0.5N
2π)(10)
n=0,1,2,3,.....,N-1
Wherein, X
8Ln () is 8 grades of comb filtering sequences, X
+ startn () is the first forward sequence, P
startfor default starting point, N
2 πfor unit periodic sequence length, (int) is round numbers, and A is signal amplitude, unit v, ω
ifor signal frequency, K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain, T is sampling interval duration, and n is series of discrete number,
be the first forward sequence initial phase, N is predetermined sequence length.
In one embodiment, described first anti-pleat sequence is formula (11):
X
-start(-n)=X
+start(N-n)=AK(ω
i)cos(-ω
iTn+β1)(11)
n=0,1,2,3,.....,N-1
Wherein, X
-start(-n) is the first anti-pleat sequence, X
+ startn () is the first forward sequence, A is signal amplitude, unit v, ω
ifor signal frequency, T is sampling interval duration, and n is series of discrete number, and β 1 is the first anti-pleat sequence initial phase, and N is predetermined sequence length.Preliminary sequence, the first forward sequence and the first anti-pleat sequence pattern are expressed as shown in Figure 3.
For step S110, the calculating of the first positive phase and the first antiphase is the result based on quadrature downconvert and integral and calculating.
When not considering the mixing interfering frequency of quadrature downconvert, quadrature downconvert is expressed as formula (12), and integral and calculating is expressed as formula (13):
Ω=ω
i-ω
s
n=0,1,2,.....,N-1
Wherein, R
+ startn () is the first positive real sequence of mixing frequently, I
+ startn () is the first weakened body resistance frequency mixing sequence, R
-start(-n) is the first anti-real sequence of mixing frequently, I
-start(-n) is the first anti-empty sequence of mixing frequently, cos (ω
sor cos (-ω Tn)
stn) be the discrete cosine function of reference frequency, sin (ω
sor sin (-ω Tn)
stn) be the discrete sine function of reference frequency, Ω is signal frequency ω
iwith reference frequency ω
sfrequency difference, T is sampling interval duration, and n is series of discrete number, K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain,
be the first forward sequence initial phase, β 1 is the first forward sequence initial phase, and N is predetermined sequence length.
n=0,1,2,.....,N-1
Wherein, R
+ startbe the first positive real integrated value frequently, unit dimensionless, I
+ startbe the first weakened body resistance frequency integrated value, unit dimensionless, R
-startbe the first anti-real integrated value frequently, unit dimensionless, I
-startbe the first anti-empty integrated value of mixing frequently, unit dimensionless, Ω is signal frequency ω
iwith reference frequency ω
sfrequency difference, T is sampling interval duration, and n is series of discrete number, and N is predetermined sequence length,
be the first forward sequence initial phase, β 1 is the first anti-pleat sequence initial phase, and N is predetermined sequence length.
In one embodiment, the calculating of the first positive phase and the first antiphase, is expressed as formula (14):
Wherein, PH
+ startbe the first positive phase, PH
-startbe the first antiphase, R
+ startbe the first positive real integrated value frequently, unit dimensionless, I
+ startbe the first weakened body resistance frequency integrated value, unit dimensionless, R
-startbe the first anti-real integrated value frequently, unit dimensionless, I
-startbe the first anti-empty integrated value of mixing frequently, unit dimensionless, Ω is signal frequency ω
iwith reference frequency ω
sfrequency difference, T is sampling interval duration, and N is predetermined sequence length,
be the first forward sequence initial phase, β 1 is the first anti-pleat sequence initial phase.
For step S111, in one embodiment, the first average initial phase computing method, are expressed as formula (15):
Wherein, PH
start-avgbe the first average initial phase, PH
+ startbe the first positive phase, PH
-startbe the first antiphase,
be the first forward sequence initial phase, β 1 is the first anti-pleat sequence initial phase.
For step S112, in one embodiment, described preset phase value can be ± π/4; According to the described first average initial phase and preset phase value, the step obtaining phase compare value can comprise:
If the described first average initial phase is more than or equal to 0 and is less than or equal to pi/2, deduct the described first average initial phase according to π/4 and obtain phase compare value;
If the described first average initial phase is more than or equal to-and pi/2 is less than or equal to 0, deducts the described first average initial phase obtain phase compare value according to-π/4.
Be specially formula (16):
Wherein, △ PH
comfor phase compare value, unit rad, PH
start-avgit is the first average initial phase.
In one embodiment, described new starting point calculates, and is formula (17):
Wherein, P
newfor new starting point, unit dimensionless, P
startfor default starting point, △ PH
comfor phase compare value, unit rad, N
2 πfor unit periodic sequence length, (int) is round numbers.
For step S113, the second forward sequence and the second anti-pleat sequence are formula (18):
X
-end(-n)=X
+end(N-n)=AK
L(ω
i)cos(-ω
iTn+β2)(18)
n=0,1,2,3,.....,N-1
Wherein, X
8Ln () is 8 grades of comb filtering sequences, X
+ endn () is the second forward sequence, X
-end(-n) is the second anti-pleat sequence, P
newfor new starting point, unit dimensionless, K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain,
be the second forward sequence initial phase, β 2 is the second anti-pleat sequence initial phase, ω
ifor signal frequency, T is sampling interval duration, and n is series of discrete number, and N is predetermined sequence length.
For step S114, the computing method of the second positive phase and the second antiphase are the results calculated based on quadrature downconvert and digital filtering.Described digital filtering is made up of 6 grades of rectangular window arithmetic mean filter of 2 kinds of filtering parameters.
When not considering the mixing interfering frequency of quadrature downconvert, quadrature downconvert is expressed as formula (19), and 6 grades of rectangular window arithmetic mean filter filtering calculation expressions of 2 kinds of filtering parameters are formula (20):
Ω=ω
i-ω
s
n=0,1,2,.....,N-1
Wherein, R
+ endn () is the second positive real sequence of mixing frequently, I
+ endn () is the second weakened body resistance frequency mixing sequence, R
-end(-n) is the second anti-real sequence of mixing frequently, I
-end(-n) is the second anti-empty sequence of mixing frequently, cos (ω
sor cos (-ω Tn)
stn) be the discrete cosine function of reference frequency, sin (ω
sor sin (-ω Tn)
stn) be the discrete sine function of reference frequency, K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain, Ω is signal frequency ω
iwith reference frequency ω
sfrequency difference, ω
ifor signal frequency, T is sampling interval duration, and n is series of discrete number,
be the first forward sequence initial phase, β 1 is the first anti-pleat sequence initial phase, and N is predetermined sequence length.
N
D=3N
D1+3N
D2
N
D≤N
n=0,1,2,3,....,N
D-1
Wherein, R
+ endbe the second positive real digital filtering final value frequently, unit dimensionless; I
+ endbe the second weakened body resistance frequency digital filtering final value, unit dimensionless; R
-endbe the second anti-digital filtering final value, unit dimensionless; I
-endbe the second anti-empty digital filtering final value frequently, unit dimensionless; K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain, Ω is signal frequency ω
iwith reference frequency ω
sfrequency difference; K (Ω) for digital filtering is in the amplitude gain of frequency difference Ω, unit dimensionless; T is sampling interval duration;
it is the second forward sequence initial phase; β 2 is the second anti-pleat sequence initial phase; N
d1for filtering parameter 1, namely to N
d1individual continuous discrete value is added, and then gets its arithmetic mean and exports as this filter value; N
d2for filtering parameter 2, namely to N
d2individual continuous discrete value is added, and then gets its arithmetic mean and exports as this filter value; N
dfor digital filtering uses sequence length, be quantitatively the summation of 6 grades of rectangular window arithmetic mean filter filtering parameters, be less than or equal to predetermined sequence length N.
In one embodiment, filtering parameter N
d1value is 1.5 times of the unit period sequence length of described reference frequency, and object carries out degree of depth suppression to the mixing interfering frequency that 1/3 subharmonic produces; Filtering parameter N
d2value is 2 times of the unit period sequence length of described reference frequency, and object carries out degree of depth suppression to the mixing interfering frequency that direct current, 1/2 gradation, subharmonic etc. produce.6 grades of rectangular window arithmetic mean filter filtering of 2 kinds of filtering parameters calculate 10.5 times that need to use signal period sequence length.
Filtering parameter N
d1with filtering parameter N
d2be calculated as formula (21):
N
D1=(int)(1.5N
2π)(21)
N
D2=2N
2π
Wherein, N
d1for digital filter parameters 1, unit dimensionless, (int) is round numbers, N
d2for digital filter parameters 2, unit dimensionless, N
2 πfor unit periodic sequence length.
In one embodiment, the computing method of the second positive phase and the second antiphase, are expressed as formula (22):
Wherein, PH
+ endbe the second positive phase, PH
-endbe the second antiphase, R
+ endbe the second positive real integrated value frequently, unit dimensionless, I
+ endbe the second weakened body resistance frequency integrated value, unit dimensionless, R
-endbe the second anti-real integrated value frequently, unit dimensionless, I
-endbe the second anti-empty integrated value of mixing frequently, unit dimensionless, Ω is signal frequency ω
iwith reference frequency ω
sfrequency difference, T is sampling interval duration, N
dfor digital filtering uses sequence length,
be the second forward sequence initial phase, β 2 is the second anti-pleat sequence initial phase.
For step S115, the second average initial phase computing method, are expressed as formula (23):
Wherein, PH
end-avgbe the second average initial phase, PH
+ endbe the second positive phase, PH
-endbe the second antiphase,
be the second forward sequence initial phase, β 2 is the second forward sequence initial phase.
For step S116, cosine function modulation sequence is expressed as formula (24):
n=0,1,2,3,.....,N-1
Wherein, X
cosn () is cosine function modulation sequence; X
+ endn () is the second forward sequence; X
-end(-n) is the second anti-pleat sequence; PH
end-avgit is the second average initial phase; AK
l(ω
i) be cosine function modulation sequence amplitude, unit v;
for cosine function modulation sequence initial phase, K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain, ω
ifor signal frequency, T is sampling interval duration, and n is series of discrete number, and N is predetermined sequence length,
be the second forward sequence initial phase, β 2 is the second anti-pleat sequence initial phase.
For step S117, sine function modulation sequence is expressed as formula (25):
n=0,1,2,3,.....,N-1
Wherein, X
sinn () is sine function modulation sequence, X
+ endn () is the second forward sequence, X
-end(-n) is the second anti-pleat sequence, PH
end-avgbe the second average initial phase, AK
l(ω
i) be sine function modulation sequence amplitude, unit v,
for cosine function modulation sequence initial phase, K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain, ω
isignal frequency, T is sampling interval duration, and n is series of discrete number, and N is predetermined sequence length,
be the second forward sequence initial phase, β 2 is the second anti-pleat sequence initial phase.
For step S118, in one embodiment, obtain zero initial phase benchmark cosine function modulation sequence, be expressed as formula (26):
Wherein, X0
cosn () is zero initial phase benchmark cosine function modulation sequence, AK
l(ω
i) be cosine function modulation sequence amplitude, unit v, ω
ifor signal frequency, K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain, T is sampling interval duration, and n is series of discrete number, and N is predetermined sequence length.
In one embodiment, obtain zero initial phase reference sinusoidal FUNCTION MODULATION sequence, be expressed as formula (27):
Wherein, X0
sinn () is zero initial phase reference sinusoidal FUNCTION MODULATION sequence, AK
l(ω
i) be sine function modulation sequence amplitude, unit is v, ω
ifor signal frequency, K
l(ω
i) for comb filtering process is at signal frequency ω
idimensionless amplitude gain, T is sampling interval duration, and n is series of discrete number, and N is predetermined sequence length.Zero initial phase reference point avatars as shown in Figure 4.
For step S119, in one embodiment, obtain zero initial phase benchmark cosine function times frequency sequence, be expressed as formula (28):
X02
cos(n)=X0
cos(n)X
cos(n)-X0
sin(n)X
sin(n)(28)
=[AK
L(ω
i)]
2cos(2ω
iT
nn)
Wherein, X02
cosn () is zero initial phase benchmark cosine function times frequency sequence, (N-1)/2 are sequence length.
Based on same inventive concept, the present invention also provides the system of a kind of acquisition zero initial phase reference sinusoidal function times frequency sequence, is described in detail embodiments of systems of the invention below in conjunction with accompanying drawing.
As shown in Figure 5, the system of a kind of acquisition zero initial phase benchmark cosine function times frequency sequence, comprising:
Preliminary sequence length determination modul 501, for the lower limit according to frequency power signal scope, presets sample frequency and default integer signal period number, obtains preliminary sequence length;
Preliminary sequence acquisition module 502, for sampling to electric power signal according to described preliminary sequence length, obtains the preliminary sequence of described electric power signal;
Reference frequency determination module 503, for carrying out frequency preliminary survey to described preliminary sequence, obtains the first synchronizing frequency of described electric power signal, obtains reference frequency according to described just synchronizing frequency;
Unit period sequence length determination module 504, for according to described default sample frequency and described reference frequency, obtains the unit period sequence length of described electric power signal;
Preprocessing sequence length determination modul 505, for being multiplied with described unit period sequence length by described default integer signal period number, obtains preprocessing sequence length;
Preprocessing sequence acquisition module 506, for according to described preprocessing sequence length, obtains preprocessing sequence from the preliminary sequence of described electric power signal;
Comb filtering sequence determination module 507, for carrying out comb filtering process to described preprocessing sequence, obtain comb filtering sequence, wherein comb filtering sequence length is the residue length of described preprocessing sequence after carrying out comb filtering process;
Predetermined sequence length determination modul 508, for determining the ratio integer of described comb filtering sequence length and described unit period sequence length, predetermined sequence length is obtained according to described ratio integer and described unit period sequence length, wherein said ratio integer is odd number, and described predetermined sequence length is odd number;
First ray acquisition module 509, for according to described predetermined sequence length and default starting point, obtains the first forward sequence from described comb filtering sequence, obtains the first anti-pleat sequence according to described first forward sequence;
First positive and negative phase determination module 510, for obtaining the first positive phase according to described first forward sequence, obtains the first antiphase according to described first anti-pleat sequence;
First average initial phase determination module 511, for obtaining the first average initial phase according to described first positive phase and described first antiphase;
New starting point determination module 512, for according to the described first average initial phase and preset phase value, obtains phase compare value, according to described phase compare value, described default starting point and described unit period sequence length, obtains new starting point;
Second retrieval module 513, for according to described predetermined sequence length and described new starting point, obtains the second forward sequence from described comb filtering sequence, obtains the second anti-pleat sequence according to the second forward sequence;
Second positive and negative phase determination module 514, for obtaining the second positive phase according to described second forward sequence, obtains the second antiphase according to described second anti-pleat sequence;
Second average initial phase determination module 515, for obtaining the second average initial phase according to described second positive phase and described second antiphase;
Cosine function modulation sequence determination module 516, for described second forward sequence being added with described second anti-pleat sequence, obtains and sequence, according to described and sequence and the described second average initial phase cosine function value, obtains cosine function modulation sequence;
Sine function modulation sequence determination module 517, for described second forward sequence and described second anti-pleat sequence being subtracted each other, obtains difference sequence, according to the sine function of described difference sequence and the described second average initial phase, obtains sine function modulation sequence;
Zero initial phase modulation sequence acquisition module 518, for exporting from described cosine function modulation sequence central point, obtain zero initial phase benchmark cosine function modulation sequence, export from described sine function modulation sequence central point, obtain zero initial phase reference sinusoidal FUNCTION MODULATION sequence;
Zero initial phase benchmark cosine function times frequency sequence determination module 519, for by described zero initial phase benchmark cosine function modulation sequence square with square the subtracting each other of described zero initial phase reference sinusoidal FUNCTION MODULATION sequence, obtain zero initial phase benchmark cosine function times frequency sequence.
In one embodiment, described cosine function modulation sequence determination module 516 is according to expression formula
obtain cosine function modulation sequence X
cos(n), wherein, X
+ endn () is the second forward sequence, X
-end(-n) is the second anti-pleat sequence, PH
end-avgit is the second average initial phase.
In one embodiment, described sine function modulation sequence determination module 517 can according to expression formula
obtain sine function modulation sequence X
sin(n), wherein, X
+ endn () is the second forward sequence, X
-end(-n) is the second anti-pleat sequence, PH
end-avgit is the second average initial phase.
In one embodiment, described zero initial phase modulation sequence acquisition module 518 can according to expression formula
obtain described zero initial phase benchmark cosine function modulation sequence X0
cos(n), wherein,
n is series of discrete number, and N is predetermined sequence length, X
cosn () is cosine function modulation sequence.
In one embodiment, described zero initial phase modulation sequence acquisition module 518 can according to expression formula
obtain described zero initial phase reference sinusoidal FUNCTION MODULATION sequence X 0
sin(n), wherein,
n is series of discrete number, and N is predetermined sequence length, X
sinn () is sine function modulation sequence.
Other technical characteristic of present system is identical with the inventive method, does not repeat them here.
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. obtain a method for zero initial phase benchmark cosine function times frequency sequence, it is characterized in that, comprise step:
According to the lower limit of frequency power signal scope, default sample frequency and default integer signal period number, obtain preliminary sequence length;
According to described preliminary sequence length, electric power signal is sampled, obtain the preliminary sequence of described electric power signal;
Frequency preliminary survey is carried out to described preliminary sequence, obtains the first synchronizing frequency of described electric power signal, obtain reference frequency according to described just synchronizing frequency;
According to described default sample frequency and described reference frequency, obtain the unit period sequence length of described electric power signal;
Described default integer signal period number is multiplied with described unit period sequence length, obtains preprocessing sequence length;
According to described preprocessing sequence length, from the preliminary sequence of described electric power signal, obtain preprocessing sequence;
Carry out comb filtering process to described preprocessing sequence, obtain comb filtering sequence, wherein comb filtering sequence length is the residue length of described preprocessing sequence after carrying out comb filtering process;
Determine the ratio integer of described comb filtering sequence length and described unit period sequence length, obtain predetermined sequence length according to described ratio integer and described unit period sequence length, wherein said ratio integer is odd number, and described predetermined sequence length is odd number;
According to described predetermined sequence length and default starting point, from described comb filtering sequence, obtain the first forward sequence, obtain the first anti-pleat sequence according to described first forward sequence;
Obtain the first positive phase according to described first forward sequence, obtain the first antiphase according to described first anti-pleat sequence;
The first average initial phase is obtained according to described first positive phase and described first antiphase;
According to the described first average initial phase and preset phase value, obtain phase compare value, according to described phase compare value, described default starting point and described unit period sequence length, obtain new starting point;
According to described predetermined sequence length and described new starting point, from described comb filtering sequence, obtain the second forward sequence, obtain the second anti-pleat sequence according to the second forward sequence;
Obtain the second positive phase according to described second forward sequence, obtain the second antiphase according to described second anti-pleat sequence;
The second average initial phase is obtained according to described second positive phase and described second antiphase;
Described second forward sequence is added with described second anti-pleat sequence, obtains and sequence, according to described and sequence and the described second average initial phase cosine function value, obtain cosine function modulation sequence;
Described second forward sequence and described second anti-pleat sequence are subtracted each other, obtains difference sequence, according to the sine function of described difference sequence and the described second average initial phase, obtain sine function modulation sequence;
Export from described cosine function modulation sequence central point, obtain zero initial phase benchmark cosine function modulation sequence, export from described sine function modulation sequence central point, obtain zero initial phase reference sinusoidal FUNCTION MODULATION sequence;
By described zero initial phase benchmark cosine function modulation sequence square with square the subtracting each other of described zero initial phase reference sinusoidal FUNCTION MODULATION sequence, obtain zero initial phase benchmark cosine function times frequency sequence.
2. the method for acquisition zero initial phase benchmark cosine function times frequency sequence according to claim 1, is characterized in that, according to expression formula
obtain described zero initial phase benchmark cosine function modulation sequence X0
cos(n), wherein,
n is series of discrete number, and N is predetermined sequence length, X
cosn () is cosine function modulation sequence.
3. the method for acquisition zero initial phase benchmark cosine function times frequency sequence according to claim 1, is characterized in that, according to expression formula
obtain described zero initial phase reference sinusoidal FUNCTION MODULATION sequence X 0
sin(n), wherein,
n is series of discrete number, and N is predetermined sequence length, X
sinn () is sine function modulation sequence.
4. the method for acquisition zero initial phase benchmark cosine function times frequency sequence according to claim 1, is characterized in that, according to expression formula
obtain cosine function modulation sequence X
cos(n), wherein, X
+ endn () is the second forward sequence, X
-end(-n) is the second anti-pleat sequence, PH
end-avgit is the second average initial phase.
5. the method for acquisition zero initial phase benchmark cosine function times frequency sequence according to claim 1, is characterized in that, according to expression formula
obtain sine function modulation sequence X
sin(n), wherein, X
+ endn () is the second forward sequence, X
-end(-n) is the second anti-pleat sequence, PH
end-avgit is the second average initial phase.
6. obtain a system for zero initial phase benchmark cosine function times frequency sequence, it is characterized in that, comprising:
Preliminary sequence length determination modul, for the lower limit according to frequency power signal scope, presets sample frequency and default integer signal period number, obtains preliminary sequence length;
Preliminary sequence acquisition module, for sampling to electric power signal according to described preliminary sequence length, obtains the preliminary sequence of described electric power signal;
Reference frequency determination module, for carrying out frequency preliminary survey to described preliminary sequence, obtains the first synchronizing frequency of described electric power signal, obtains reference frequency according to described just synchronizing frequency;
Unit period sequence length determination module, for according to described default sample frequency and described reference frequency, obtains the unit period sequence length of described electric power signal;
Preprocessing sequence length determination modul, for being multiplied with described unit period sequence length by described default integer signal period number, obtains preprocessing sequence length;
Preprocessing sequence acquisition module, for according to described preprocessing sequence length, obtains preprocessing sequence from the preliminary sequence of described electric power signal;
Comb filtering sequence determination module, for carrying out comb filtering process to described preprocessing sequence, obtain comb filtering sequence, wherein comb filtering sequence length is the residue length of described preprocessing sequence after carrying out comb filtering process;
Predetermined sequence length determination modul, for determining the ratio integer of described comb filtering sequence length and described unit period sequence length, predetermined sequence length is obtained according to described ratio integer and described unit period sequence length, wherein said ratio integer is odd number, and described predetermined sequence length is odd number;
First ray acquisition module, for according to described predetermined sequence length and default starting point, obtains the first forward sequence from described comb filtering sequence, obtains the first anti-pleat sequence according to described first forward sequence;
First positive and negative phase determination module, for obtaining the first positive phase according to described first forward sequence, obtains the first antiphase according to described first anti-pleat sequence;
First average initial phase determination module, for obtaining the first average initial phase according to described first positive phase and described first antiphase;
New starting point determination module, for according to the described first average initial phase and preset phase value, obtains phase compare value, according to described phase compare value, described default starting point and described unit period sequence length, obtains new starting point;
Second retrieval module, for according to described predetermined sequence length and described new starting point, obtains the second forward sequence from described comb filtering sequence, obtains the second anti-pleat sequence according to the second forward sequence;
Second positive and negative phase determination module, for obtaining the second positive phase according to described second forward sequence, obtains the second antiphase according to described second anti-pleat sequence;
Second average initial phase determination module, for obtaining the second average initial phase according to described second positive phase and described second antiphase;
Cosine function modulation sequence determination module, for described second forward sequence being added with described second anti-pleat sequence, obtains and sequence, according to described and sequence and the described second average initial phase cosine function value, obtains cosine function modulation sequence;
Sine function modulation sequence determination module, for described second forward sequence and described second anti-pleat sequence being subtracted each other, obtains difference sequence, according to the sine function of described difference sequence and the described second average initial phase, obtains sine function modulation sequence;
Zero initial phase modulation sequence acquisition module, for exporting from described cosine function modulation sequence central point, obtain zero initial phase benchmark cosine function modulation sequence, export from described sine function modulation sequence central point, obtain zero initial phase reference sinusoidal FUNCTION MODULATION sequence;
Zero initial phase benchmark cosine function times frequency sequence determination module, for by described zero initial phase benchmark cosine function modulation sequence square with square the subtracting each other of described zero initial phase reference sinusoidal FUNCTION MODULATION sequence, obtain zero initial phase benchmark cosine function times frequency sequence.
7. the system of acquisition zero initial phase benchmark cosine function times frequency sequence according to claim 6, it is characterized in that, described zero initial phase modulation sequence acquisition module is according to expression formula
obtain described zero initial phase benchmark cosine function modulation sequence X0
cos(n), wherein,
n is series of discrete number, and N is predetermined sequence length, X
cosn () is cosine function modulation sequence.
8. the system of acquisition zero initial phase benchmark cosine function times frequency sequence according to claim 6, it is characterized in that, described zero initial phase modulation sequence acquisition module is according to expression formula
obtain described zero initial phase reference sinusoidal FUNCTION MODULATION sequence X 0
sin(n), wherein,
n is series of discrete number, and N is predetermined sequence length, X
sinn () is sine function modulation sequence.
9. the system of acquisition zero initial phase benchmark cosine function times frequency sequence according to claim 6, it is characterized in that, described cosine function modulation sequence determination module is according to expression formula
obtain cosine function modulation sequence X
cos(n), wherein, X
+ endn () is the second forward sequence, X
-end(-n) is the second anti-pleat sequence, PH
end-avgit is the second average initial phase.
10. the system of acquisition zero initial phase benchmark cosine function times frequency sequence according to claim 6, it is characterized in that, described sine function modulation sequence determination module is according to expression formula
obtain sine function modulation sequence X
sin(n), wherein, X
+ endn () is the second forward sequence, X
-end(-n) is the second anti-pleat sequence, PH
end-avgit is the second average initial phase.
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