CN106970265B - A method of harmonic parameters are estimated using the incomplete S-transformation of Multiple Time Scales - Google Patents
A method of harmonic parameters are estimated using the incomplete S-transformation of Multiple Time Scales Download PDFInfo
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- G01R23/16—Spectrum analysis; Fourier analysis
Abstract
The invention discloses a kind of using 3 functional modules such as the methods, including time scale determining module (1), incomplete S-transformation computing module (2), harmonic parameters estimation module (3) of the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales；Time scale determining module (1) determines the sampling of data ratio that each concern Frequency point calculates according to frequency ratio rule, when the points of data from the sample survey reach setting value, just it exports to incomplete S-transformation computing module (2) and incomplete S-transformation calculating, the parameters such as instantaneous amplitude, phase and frequency of complex vector located estimation harmonic wave that harmonic parameters estimation module (3) is obtained according to incomplete S-transformation computing module (2) is carried out to the Frequency point.The present invention provides new mode for the real-time analysis of each frequency component of wide frequency domain signal.
Description
Technical field
The present invention relates to harmonic parameters to estimate field, in particular to a kind of using the incomplete S-transformation estimation of Multiple Time Scales
The method of harmonic parameters.
Background technique
Modern power systems continue to develop, and the industrial technologies such as micro-capacitance sensor, electric railway and smelting constantly upgrade, and run
Operating condition is increasingly complicated and contains large-scale nonlinear power device, makes the complicated harmonic penetration of a large amount of wide frequency domain non-stationaries to public
Power grid causes system resonance, ageing equipment and protective device malfunction etc. to endanger, therefore must administer to complicated harmonic wave, and right
Its parameter accurately estimates it is the premise administered.
The parameters such as amplitude, frequency and the phase of complicated harmonic wave have time variation, when traditional Fourier's analysis method does not have
Frequency part characterization ability, can not accurately detect non-stationary harmonic wave, therefore need to seek have preferable analysis ability to divide time varying signal
Analysis method.Common Time-frequency method such as wavelet transformation is it needs to be determined that Decomposition order and selection mother wavelet, coefficient cannot be characterized directly
Harmonic parameters, to noise-sensitive and computationally intensive, it is difficult to application in real time needs the analysis of complicated harmonic wave a kind of more intuitive, real
When and stable Time-Frequency Analysis Method.S-transformation has intuitive time-frequency characteristic as time-frequency analysis technology, can be from its feature
Vector directly extracts the amplitude and phase of signal, but its transit time is grown and complicates when being also difficult to use in the big problem of operand
The real-time accurate estimation of harmonic parameters.Incomplete S-transformation is calculated only for concern Frequency point, under the premise of retaining effective information,
Operand is substantially reduced, creates possibility for application in real time.But incomplete S-transformation is still to be estimated for complicated harmonic parameters
It need to solve the problems such as concern Frequency point detects, transit time is too long, elimination end effect, frequency dividing real-time tracking.
Incomplete S-transformation is applied to complicated harmonic parameters and accurately estimated in real time by the present invention, to concern Frequency point using not
Same time scale guarantees each frequency content real-time performance of tracking and estimation accuracy, overcomes conventional Fourier transform method to non-flat
Steady signal can not Accurate Analysis limitation, while it is big to solve common Time-Frequency Analysis Method operand, it is difficult to the difficulties such as application in real time
Topic.
Summary of the invention
The present invention provides a kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales, for data
FFT spectrum pays close attention to Frequency point, using ginsengs such as instantaneous amplitude, frequency and the phases of Multiple Time Scales estimation each frequency component of harmonic wave
Number, the present invention can improve the real-time performance of tracking to data analysis.
A method of estimating that harmonic parameters, this method are true using time scale using the incomplete S-transformation of Multiple Time Scales
Cover half block (1), incomplete S-transformation computing module (2), harmonic parameters estimation module (3) totally 3 sequentially connected functional modules；
Time scale determining module (1) is used to determine the sampling of data ratio that each concern Frequency point calculates, and the data of sampling are distinguished
The buffer area of the uniform length of each Frequency point is distributed in deposit, is filled up once the buffer area of some Frequency point is sampled data,
Just it exports to incomplete S-transformation computing module (2) and carries out incomplete S-transformation calculating, if there are two the buffer areas of frequencies above point
It is filled simultaneously, is then lined up from big to small according to concern Frequency point serial number and the data of buffer area are sent into incomplete S-transformation calculating
Module (2) is calculated, and harmonic parameters estimation module (3) complex vector located is estimated according to what incomplete S-transformation computing module (2) obtained
Count instantaneous amplitude, the phase and frequency parameter of harmonic wave.
A kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales, time scale determine mould
Block (1) determines the sampling proportion that each concern Frequency point calculates according to frequency ratio rule, and the frequency ratio rule is using as follows
Calculate step:
A1: 10 fundamental frequency cycles data of acquisition do FFT operation, are identified according to the power spectral envelope Dynamic Measurement of FFT spectrum
The concern Frequency point of data, the number for paying close attention to Frequency point are denoted as M, and the serial number of M concern Frequency point is followed successively by n from small to large1,
n2..., nM, enter step A2；
A2: the corresponding frequency of each concern Frequency point is calculated according to the following formula:
fi=ni/ (NT), i=1,2 ..., M
N is total points of data in formula, and T is the sampling period, and NT is the total duration of data, enters step A3；
A3: the buffer area that 1 length is L=W × V is distributed to each concern Frequency point, W is to extract coefficient, and V is data fi
The analysis cycle of frequency component, W takes the integer between 5~10 when calculating, and V takes the integer greater than 3, enters step A4；
A4: sample frequency f is calculatedsWith concern Frequency point respective frequencies fiRatio and rounding:
Ii=int [fs/(W×fi)], i=1,2 ..., M
Int [] indicates round operation in formula, enters step A5；
A5: I is pressediInterval extracts data and is stored in corresponding buffer area respectively, once the buffer area of some Frequency point is sampled
Data are filled up, and are just exported to incomplete S-transformation computing module (2) and are carried out incomplete S-transformation calculating, if there are two frequencies above points
Buffer area be filled simultaneously, then according to its respective frequencies fiIt is lined up from high to low and the data of buffer area is sent into incomplete S change
Computing module (2) is changed to be calculated.
A kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales, harmonic parameters estimate mould
Block (3) realizes harmonic parameters estimation according to the calculated result of incomplete S-transformation computing module (2), calculates step using following:
B1: according to incomplete S-transformation computing module (2) to Frequency point niCalculated result, i.e., complex vector located v extracts v's
Data of middle part section is denoted as vc, vcPoints are L1=L-2W, i.e. the discarding each W point data in the both ends v, enter step B2；
B2: to complex vector located vcAmplitude is sought, data respective frequencies f is obtainediThe estimation of the harmonic wave instantaneous amplitude vector of component
Value, it may be assumed that
Enter step B3；
B3: v is calculatedcDynamic argument Φ vector, Φ=actan [imag (vc)/real(vc)], actan [] is indicated in formula
It negates tangent, imaginary part is sought in imag () expression, and real () indicates realistic portion, enters step B4；
B4: the estimated value of instantaneous frequency vector is sought using following formula:
T in formulasIn sampling period after indicating sampling, enter step B5；
B5: the estimated value of instantaneous phase vector is acquired using following formula:
% indicates modulus operation, Φ in formula0For the initial value of Φ vector, obtained by following formula:
K in formula0The midpoint serial number for indicating Φ vector, enters step B6；
B6: the estimated value of the corresponding harmonic component instantaneous amplitude vector of the Frequency point, frequency vector and phase vectors is exportedComplete the parameter Estimation of the data.
For the time scale determining module (1) using in the calculating step of frequency ratio rule, step A3 gives each concern
It is the buffer area L that Frequency point, which distributes 1 length, and output is being followed to incomplete S-transformation computing module (2) after data fill up buffer area
In ring calculating process, the data in buffer area are updated using following steps:
C1: buffer data moves to left the position (L-2W), enters step C2；
C2: the data newly extracted are filled the position (L-2W-1) on the right side of the buffer area, buffer area fill up after according to right
2 step A5 of requirement is handled, return step C1, so updates data in buffer area in cycles.
The data of incomplete S-transformation computing module (2) the input time scale determining module (1) carry out incomplete S change
It changes, only estimates a certain fiThe parameter of frequency component need to only calculate an incomplete S-transformation vector, do FFT transform to data
Afterwards, the stepped-frequency signal for serial number L/W does the transformation of adding window inverse FFT to get the f is arrivediThe incomplete S-transformation knot of frequency component
Fruit.
The incomplete S-transformation computing module (2) is dry to eliminate DC spectral before carrying out incomplete S-transformation to data
It disturbs, zero-mean processing is done to input data, that is, following formula is used to make the mean value zero of input data:
Di=Di- mean (Di)
D in formulaiFor the data of input, mean () expression is averaged.
Detailed description of the invention
Fig. 1 is functional module and work flow diagram of the invention.
Fig. 2 is frequency ratio of the present invention sampling schematic diagram.
Fig. 3 is concern Frequency point Multiple Time Scales schematic diagram of the present invention.
Specific embodiment
To solve the problems, such as that complicated harmonic parameters real-time estimation, the present invention provide a kind of using the incomplete S change of Multiple Time Scales
The method for changing estimation harmonic parameters, is illustrated preferred embodiment example of the invention below in conjunction with attached drawing, it should be noted that
Preferred embodiment example is in order to further illustrate the present invention, rather than limiting the scope of protection of the present invention.
Fig. 1 is a kind of function of method that harmonic parameters are estimated using the incomplete S-transformation of Multiple Time Scales of the present invention
Module and work flow diagram.
As shown in Figure 1, a kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales, this method use
Time scale determining module (1), incomplete S-transformation computing module (2), harmonic parameters estimation module (3) totally 3 it is sequentially connected
Functional module；Time scale determining module (1) is used to determine the sampling proportion that each concern Frequency point calculates, and by the data of sampling
The buffer area of the uniform length of each Frequency point is distributed in deposit respectively, is filled out once the buffer area of some Frequency point is sampled data
It is full, it just exports to incomplete S-transformation computing module (2) and carries out incomplete S-transformation calculating, if there are two the bufferings of frequencies above point
Area is filled simultaneously, then is lined up from big to small according to concern Frequency point serial number the data of buffer area being sent into incomplete S-transformation meter
It calculates module (2) to be calculated, harmonic parameters estimation module (3) obtains complex vector located according to incomplete S-transformation computing module (2)
Estimate instantaneous amplitude, the phase and frequency parameter of harmonic wave.
Timing detection and estimated value can be used in the detection concern Frequency point judgement of time scale determining module shown in Fig. 1 (1)
The strategy that change rate combines；Timing detection cycle can be set as 5 seconds~1 minute；Estimated value change rate is according to harmonic parameters
The change conditions given threshold of estimated value decides whether that carrying out concern Frequency point detects, i.e., estimated value does not change or changes less then
Without detection, detected if changing the threshold value more than setting；Above-mentioned strategy can rationally be selected according to practical application
It selects.
A kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales, time scale determine
Module (1) determines the sampling proportion that each concern Frequency point calculates according to frequency ratio rule, and the frequency ratio rule is using such as
Lower calculating step:
A1: 10 fundamental frequency cycles data of acquisition do FFT operation, are identified according to the power spectral envelope Dynamic Measurement of FFT spectrum
The concern Frequency point of data, the number for paying close attention to Frequency point are denoted as M, and the serial number of M concern Frequency point is followed successively by n from small to large1,
n2..., nM, enter step A2；
A2: the corresponding frequency of each concern Frequency point is calculated according to the following formula:
fi=ni/ (NT), i=1,2 ..., M
N is total points of data in formula, and T is the sampling period, and NT is the total duration of data, enters step A3；
A3: the buffer area that 1 length is L=W × V is distributed to each concern Frequency point, W is to extract coefficient, and V is data fi
The analysis cycle of frequency component, W takes the integer between 5~10 when calculating, and V takes the integer greater than 3, enters step A4；
A4: sample frequency f is calculatedsWith concern Frequency point respective frequencies fiRatio and rounding:
Ii=int [fs/(W×fi)], i=1,2 ..., M
Int [] indicates round operation in formula, enters step A5；
A5: I is pressediInterval extracts data and is stored in corresponding buffer area respectively, once the buffer area of some Frequency point is sampled
Data are filled up, and are just exported to incomplete S-transformation computing module (2) and are carried out incomplete S-transformation calculating, if there are two frequencies above points
Buffer area be filled simultaneously, then according to its respective frequencies fiIt is lined up from high to low and the data of buffer area is sent into incomplete S change
Computing module (2) is changed to be calculated.
Fig. 2 show frequency ratio sampling schematic diagram of the present invention, and initial data also includes 3 times in addition to fundamental wave in Fig. 2
With 5 subharmonic, totally 3 concern Frequency points；Initial data sample frequency is 10kHz, takes W=5 according to frequency ratio rule, then 5
The sampling interval of subharmonic is 10k/250/5=8, and the sampling interval of 3 subharmonic is 10k/150/5=13, between the sampling of fundamental wave
It is divided into 10k/50/5=40.
Fig. 2 original signal is extracted according to frequency ratio rule, being stored in length respectively is L=W × V=5 × 5=25
5 subharmonic respective frequencies dot buffer zones, 3 subharmonic respective frequencies dot buffer zones and dfundamental-harmonic pair answer frequency dot buffer zone, such as Fig. 3
Shown, the data points of 3 buffer areas are that the time interval of two data in 25,5 subharmonic respective frequencies dot buffer zones is 8
× 0.1ms, the time interval of two data is 13 × 0.1ms in 3 subharmonic respective frequencies dot buffer zones, and dfundamental-harmonic pair answers Frequency point
The time interval of two data is 40 × 0.1ms, 5 subharmonic, 3 subharmonic and 3 frequency dot buffer zone of fundamental wave 25 in buffer area
The corresponding time scale of data is respectively 20ms, 32.5ms and 100ms.
A kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales, harmonic parameters estimate mould
Block (3) realizes harmonic parameters estimation according to the calculated result of incomplete S-transformation computing module (2), calculates step using following:
B1: according to incomplete S-transformation computing module (2) to Frequency point niCalculated result, i.e., complex vector located v extracts v's
Data of middle part section is denoted as vc, vcPoints are L1=L-2W, i.e. the discarding each W point data in the both ends v, enter step B2；
B2: to complex vector located vcAmplitude is sought, data respective frequencies f is obtainediThe estimation of the harmonic wave instantaneous amplitude vector of component
Value, it may be assumed that
Enter step B3；
B3: v is calculatedcDynamic argument Φ vector, Φ=actan [imag (vc)/real(vc)], actan [] is indicated in formula
It negates tangent, imaginary part is sought in imag () expression, and real () indicates realistic portion, enters step B4；
B4: the estimated value of instantaneous frequency vector is sought using following formula:
T in formulasIn sampling period after indicating sampling, enter step B5；
B5: the estimated value of instantaneous phase vector is acquired using following formula:
% indicates modulus operation, Φ in formula0For the initial value of Φ vector, obtained by following formula:
K in formula0The midpoint serial number for indicating Φ vector, enters step B6；
B6: the estimated value of the corresponding harmonic component instantaneous amplitude vector of the Frequency point, frequency vector and phase vectors is exportedComplete the parameter Estimation of the data.
For the time scale determining module (1) using in the calculating step of frequency ratio rule, step A3 gives each concern
It is the buffer area L that Frequency point, which distributes 1 length, and output is being followed to incomplete S-transformation computing module (2) after data fill up buffer area
In ring calculating process, the data in buffer area are updated using following steps:
C1: buffer data moves to left the position (L-2W), enters step C2；
C2: the data newly extracted are filled the position (L-2W-1) on the right side of the buffer area, buffer area fill up after according to right
2 step A5 of requirement is handled, return step C1, so updates data in buffer area in cycles.
The data of incomplete S-transformation computing module (2) the input time scale determining module (1) carry out incomplete S change
It changes, only estimates a certain frequency fiThe parameter of component need to only calculate an incomplete S-transformation vector, do FFT transform to data
Afterwards, the stepped-frequency signal for serial number L/W does the transformation of adding window inverse FFT to get the f is arrivediThe incomplete S-transformation knot of frequency component
Fruit.
The incomplete S-transformation computing module (2) is dry to eliminate DC spectral before carrying out incomplete S-transformation to data
It disturbs, zero-mean processing is done to input data, that is, following formula is used to make the mean value zero of input data:
Di=Di- mean (Di)
D in formulaiFor the data of input, mean () expression is averaged.
It is an advantage of the current invention that using different analysis time scales, each Frequency point buffering for different frequency point
The length in area is consistent, in this way the calculation amount in subsequent incomplete S-transformation computing module (2) and harmonic parameters estimation module (3)
Equally, it is ensured that calculating process reduces the calculation amount of data low frequency component to data high fdrequency component real-time tracking.
The embodiment of invention described above not becomes the restriction of the scope of the present invention, if to the present invention
Embodiment carries out various deformations or amendments, but still within the spirit and principles in the present invention, should be included in power of the invention
Within the scope of benefit is claimed.
Claims (4)
1. a kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales, this method are determined using time scale
Module (1), incomplete S-transformation computing module (2), harmonic parameters estimation module (3) totally 3 sequentially connected functional modules,
It is characterized in that, time scale determining module (1) is used to determine the sampling of data ratio that each concern Frequency point calculates, and by sampling
Data are stored in the buffer area for distributing to the uniform length of each Frequency point respectively, once the buffer area of some Frequency point is sampled number
It according to filling up, just exports to incomplete S-transformation computing module (2) and carries out incomplete S-transformation calculating, if there are two frequencies above points
Buffer area is filled simultaneously, then is lined up from big to small according to concern Frequency point serial number the data of buffer area being sent into incomplete S change
It changes computing module (2) to be calculated, the plural number that harmonic parameters estimation module (3) is obtained according to incomplete S-transformation computing module (2)
Vector estimates the instantaneous amplitude of harmonic wave, phase and frequency parameter.
2. a kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales according to claim 1, at that time
Between scale determining module (1) sampling of data ratio that each concern Frequency point calculates determined according to frequency ratio rule, feature exists
In the frequency ratio rule calculates step using following:
A1: 10 fundamental frequency cycles data of acquisition do FFT operation, identify data according to the power spectral envelope Dynamic Measurement of FFT spectrum
Concern Frequency point, the number for paying close attention to Frequency point is denoted as M, and the serial number of M concern Frequency point is followed successively by n from small to large1, n2...,
nM, enter step A2；
A2: the corresponding frequency of each concern Frequency point is calculated according to the following formula:
fi=ni/ (NT), i=1,2 ..., M
N is total points of data in formula, and T is the sampling period, and NT is the total duration of data, enters step A3；
A3: the buffer area that 1 length is L=W × V is distributed to each concern Frequency point, W is to extract coefficient, and V is data fiFrequency
The analysis cycle of component, W takes the integer between 5~10 when calculating, and V takes the integer greater than 3, enters step A4；
A4: sample frequency f is calculatedsWith concern Frequency point respective frequencies fiRatio and rounding:
Ii=int [fs/(W×fi)], i=1,2 ..., M
Int [] indicates round operation in formula, enters step A5；
A5: I is pressediInterval extracts data and is stored in corresponding buffer area respectively, fills out once the buffer area of some Frequency point is sampled data
It is full, it just exports to incomplete S-transformation computing module (2) and carries out incomplete S-transformation calculating, if there are two the bufferings of frequencies above point
Area is filled simultaneously, then according to its respective frequencies fiIt is lined up from high to low and the data of buffer area is sent into incomplete S-transformation calculating
Module (2) is calculated.
3. a kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales according to claim 1, described
Harmonic parameters estimation module (3) realizes harmonic parameters estimation according to the calculated result of incomplete S-transformation computing module (2), special
Sign is that estimation harmonic parameters calculate step using following:
B1: according to incomplete S-transformation computing module (2) to Frequency point niCalculated result, i.e., complex vector located v extracts the middle part of v
Data segment is denoted as vc, vcPoints are L1=L-2W, i.e. the discarding each W point data in the both ends v, enter step B2；
B2: to complex vector located vcAmplitude is sought, data respective frequencies f is obtainediThe estimated value of the harmonic wave instantaneous amplitude vector of component, it may be assumed that
Enter step B3；
B3: v is calculatedcDynamic argument Φ vector, Φ=actan [imag (vc)/real(vc)], actan [] expression is negated in formula
Imaginary part is sought in tangent, imag () expression, and real () indicates realistic portion, enters step B4；
B4: the estimated value of instantaneous frequency vector is sought using following formula:
T in formulasIn sampling period after indicating sampling, enter step B5；
B5: the estimated value of instantaneous phase vector is acquired using following formula:
% indicates modulus operation, Φ in formula0For the initial value of Φ vector, obtained by following formula:
K in formula0The midpoint serial number for indicating Φ vector, enters step B6；
B6: the estimated value of the corresponding harmonic component instantaneous amplitude vector of the Frequency point, frequency vector and phase vectors is exportedComplete the parameter Estimation of the data.
4. a kind of method using the incomplete S-transformation estimation harmonic parameters of Multiple Time Scales according to claim 1, at that time
Between in calculating step of the scale determining module (1) using frequency ratio rule described in claim 2, step A3 to each concern frequently
It is the buffer area L that rate point, which distributes 1 length, and data export after filling up buffer area to incomplete S-transformation computing module (2), feature
It is, in loop calculation, the data in buffer area are updated using following steps:
C1: buffer data moves to left the position (L-2W), enters step C2；
C2: the data newly extracted are filled the position (L-2W-1) on the right side of the buffer area, buffer area fill up after according to claim
2 step A5 of item are handled, and return step C1 so updates data in buffer area in cycles.
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Effective date of registration: 20211122 Address after: No. 12-8, Yan village, Danyun Road, Danyang community, Hengxi street, Jiangning District, Nanjing, Jiangsu 210000 Patentee after: JIANGSU QIFENG POWER TECHNOLOGY Co.,Ltd. Address before: 233000 No.9, 1st floor, Xianghe Jiayuan, Xinhuai Road, Dongsheng Street, Longzihu District, Bengbu City, Anhui Province Patentee before: Bengbu Qibang Science and Technology Information Consulting Co.,Ltd. |
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