CN115825557A - Generalized harmonic analysis method, device and medium based on harmonic component zero setting - Google Patents
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Abstract
The invention discloses a generalized harmonic analysis method, a generalized harmonic analysis device and a generalized harmonic analysis medium based on harmonic component zeroing, wherein the generalized harmonic analysis method, the generalized harmonic analysis device and the generalized harmonic analysis medium comprise the steps of obtaining a discrete power grid signal; windowing the power grid signal, and obtaining a windowed signal; carrying out FFT (fast Fourier transform) on the windowed signal, and analyzing m-order harmonic waves; determining three maximum spectral lines, determining the amplitudes of the three spectral lines, and determining a three-spectral-line correction formula; obtaining a fitting signal through the parameters subjected to the three-spectral-line interpolation; judging whether the new signal is smaller than a signal amplitude threshold value or not; carrying out error analysis; according to the invention, the harmonic parameters at the position are calculated by utilizing the maximum three spectral lines as an interpolation algorithm during each time of scanning the frequency spectrum, then, the signals of the calculation points are constructed, the signals are subtracted from the signals before the interpolation of the three spectral lines to obtain new signals, the new signals are subjected to the three spectral line calculation again, and the calculation is finished until the signal values are all smaller than the set threshold value, so that the analysis method has higher accuracy, and the high-precision measurement of the generalized harmonic is realized.
Description
Technical Field
The invention relates to the field of harmonic analysis, in particular to a generalized harmonic analysis method, device and medium based on harmonic component zeroing.
Background
Accurate analysis of harmonic waves/inter-harmonic waves in the power grid is the primary condition for effectively governing generalized harmonic waves. The harmonic/inter-harmonic analysis method mostly adopts a windowing interpolation algorithm based on Fourier transform. In the current research on windowing interpolation algorithm, the fundamental wave is usually found in the 45-55Hz frequency band, and then each subharmonic/interharmonic is found according to the integral multiple or fractional multiple of the fundamental wave. In this way, inter-harmonic frequency points may be missed, and only frequency characteristics at the points are analyzed, not necessarily real frequency spectrums. For example, analysis at a half fundamental frequency can only yield inter-harmonic characteristics with a resolution of 25Hz at a 50Hz fundamental frequency. For another example, when the fundamental frequency is 50.1Hz, the frequency at the third harmonic found by the frequency doubling method is 150.3Hz, while in an actual power grid, the frequency at the third harmonic may not be 150.3Hz.
Disclosure of Invention
The invention aims to solve the technical problem that incomplete and inaccurate results from possible harmonic missing, and aims to provide a generalized harmonic analysis method, device and medium based on harmonic component zeroing, which can accurately search each harmonic and meet the integrity of power grid harmonic analysis.
The invention is realized by the following technical scheme:
a generalized harmonic analysis method based on harmonic component zeroing comprises the following steps:
s1, obtaining a discrete power grid signal x (n),
where m is the harmonic order, H is the highest harmonic order, A m Is the amplitude of the m-th harmonic,
is the phase of the m-th harmonic, f 0 Is the fundamental frequency, f s Is the sampling frequency, n is the nth sampling point;
windowing w (n) processing is carried out on the power grid signal x (n), and a windowed signal x after windowing is obtained w (n)，
Wherein N is the number of sampling points;
for the windowed signal x w (n) performing FFT conversion, analyzing m-th harmonic wave to obtain a signal X (k delta f),
wherein Δ f = f s where/N is the frequency resolution, W (-) is the spectral function of a given window function,
is the window function width, j is the imaginary part, k is the harmonic times; (ii) a
S2, setting a signal amplitude threshold value;
s3, determining three maximum spectral lines on the signal X (k delta f), determining the amplitudes of the three spectral lines, and sequentially naming the three spectral lines as y 1 ，y 2 ，y 3 And determining the variables
And determining a three spectral line correction formula
Obtaining parameters after three spectral line interpolation through a correction formula, wherein the parameters comprise frequency, amplitude and phase,
s4, obtaining a fitting signal through the parameters subjected to the three-spectral-line interpolation,
calculating to obtain a new signal x' m (n)，x' m (n)＝x(n)-x m (n)；
S5, judging a new signal x' m (n) is smaller than the signal amplitude threshold value, if not, x (n) = x' m (n), and repeating steps S1-S4; if yes, x 'is output' m (n)；
S6, new signal x' m (n) error analysis was performed.
Optionally, the power grid harmonic signal is sampled by a front-end transformer and a sampling circuit to obtain a discrete power grid signal, where the power grid harmonic signal is
And t is time, and the power grid harmonic signals comprise voltage signals and current signals.
Optionally, a specific method for obtaining the signal X (k Δ f) is:
for the windowed signal x w (n) performing an FFT transform to obtain a windowed FFT spectrum:
ignoring the spectrum peak of the negative frequency point, and analyzing the m-th harmonic wave to obtain
Optionally, the signal amplitude threshold is a harmonic amplitude that can be resolved by the minimum system energy set according to the system requirements.
Optionally, a specific method of the three-spectral-line interpolation includes:
setting k m Is the spectral line at the target frequency point, k 1 Is the spectral line with the maximum amplitude near the target frequency point, k 2 And k 3 Are each k 1 The left and right spectral lines have k in the three spectral line interpolation algorithm 1 ≠k m ，k 1 ＝k 2 +1＝k 3 -1；
Obtaining the amplitude, y, of the spectral line 1 ＝|x(k 1 Δf)|，y 2 ＝|x(k 2 Δf)|，y 3 ＝|x( k 3Δf)|；
Set variable α = k m -k 2 If-0.5. Ltoreq. Alpha. Is not less than 0.5, there is a variable
Determining a frequency correction formula: f. of m ＝k m Δf＝(k 1 +α)Δf；
Determining an amplitude correction formula:
determining a phase correction formula:
optionally, performing the error analysis further comprises: and acquiring the precision of the conventional window function interpolation algorithm and comparing the precision with the error obtained in the step S6.
A generalized harmonic analysis apparatus based on harmonic component zeroing, comprising:
an acquisition module for acquiring a discrete grid signal x (n),
a windowing processing module for performing windowing w (n) processing on the power grid signal x (n) and obtaining a windowed signal x w (n)，
Wherein N is the number of sampling points;
FFT analysis module for windowing a windowed signal x w (n) performing FFT conversion, analyzing m-th harmonic wave to obtain a signal X (k delta f),
wherein Δ f = f s N is the frequency resolution, W (-) is the spectral function of a given window function,
is the window function width, j is the imaginary part, k is the harmonic times;
an input module for setting a signal amplitude threshold;
a three-spectral-line correction module for determining the three largest spectral lines on the signal X (k Δ f) and determining the amplitudes of the three spectral lines, in turn named y 1 ，y 2 ，y 3 And determining the variables
And determining a three spectral line correction formula
A calculation module for obtaining parameters after the three spectral line interpolation by a correction formula, including frequency, amplitude and phase,
a fitting calculation module for obtaining a fitting signal through the parameters after the three-spectral-line interpolation,
and calculating to obtain a new signal x' m (n)，x' m (n)＝x(n)-x m (n)；
A judging module for judging the new signal x' m (n) is smaller than the signal amplitude threshold value, if not, x (n) = x' m (n), and iterating until the iteration is input into a three-spectral-line correction module, a calculation module and a fitting calculation module; if isIf yes, then x 'is output' m (n)；
An error analysis module for comparing the new signal x' m (n) error analysis was performed.
Optionally, the FFT analysis module includes:
FFT module for windowing a windowed signal x w (n) performing an FFT transform to obtain a windowed FFT spectrum:
an analysis module for neglecting the negative frequency point spectrum peak and obtaining the m-th harmonic wave by analysis
Optionally, the three spectral line modification module includes:
a first setting module for setting k m Is the spectral line at the target frequency point, k 1 Is the spectral line with the maximum amplitude near the target frequency point, k 2 And k 3 Are each k 1 The left and right spectral lines have k in the three spectral line interpolation algorithm 1 ≠k m ，k 1 ＝k 2 +1＝k 3 -1；
A spectral line amplitude calculation module for obtaining the amplitude, y, of the spectral line 1 ＝|x(k 1 Δf)|，y 2 ＝|x(k 2 Δf)|，y 3 ＝|x(k 3 Δf)|；
A second setting module for setting the variable α = k m -k 2 Then-0.5. Ltoreq. Alpha. Ltoreq.0.5 with the variables
A first correction module to determine a frequency correction formula: f. of m ＝k m Δf＝(k 1 +α)Δf；
A second correction module for determining an amplitude correction formula:
a third correction module for determining a phase correction equation:
a computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the steps of a method for generalized harmonic analysis based on harmonic component nulling as described above.
Compared with the prior art, the invention has the following advantages and beneficial effects:
according to the invention, the harmonic parameters at the position are calculated by utilizing the maximum three spectral lines as an interpolation algorithm during scanning the frequency spectrum each time, then, the signals of the calculation points are constructed, the signals are subtracted from the signals before the interpolation of the three spectral lines to obtain new signals, the new signals are repeatedly calculated by the three spectral lines again, and the calculation is finished until the signal values are all smaller than the set threshold value, so that the analysis method has higher accuracy, the high-precision measurement of the generalized harmonic is realized, and the method has higher practical value.
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The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the principles of the invention.
Fig. 1 is a schematic flow chart of a generalized harmonic analysis method based on harmonic component nulling according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not to be construed as limitations of the invention.
It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.
In the present invention, the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
Example one
A generalized harmonic analysis method based on harmonic component zeroing comprises the following steps:
in the first step, the harmonic signal of the power grid is assumed to be
Wherein m is not necessarily an integer but may be a decimal. Wherein t is time, and the power grid harmonic signals comprise voltage signals and current signals.
Sampling by a front-end mutual inductor and a sampling circuit to obtain a discrete power grid signal x (n),
where m is the harmonic order, H is the highest harmonic order, A m Is the amplitude of the m-th harmonic,
is the phase of the m-th harmonic, f 0 Is the fundamental frequency, f s N is the nth sample point for the sampling frequency.
And provides a specific signal model with signal parameters as shown in table 1 below.
TABLE 1 Signal parameters
Secondly, performing tuning windowing w (n) processing on the power grid signal x (n) and obtaining windowed additionWindow signal x w (n)，
Wherein N is the number of sampling points; w (n) is a windowing function.
Third, the windowed signal x is filtered w (n) performing an FFT transform to obtain a windowed FFT spectrum:
ignoring the spectrum peak of the negative frequency point, analyzing the m-th harmonic to obtain X (k delta f),
wherein Δ f = f s where/N is the frequency resolution, W (-) is the spectral function of a given window function,
is the window function width, j is the imaginary part, k is the harmonic number;
fourthly, setting a signal amplitude threshold value; the signal amplitude threshold is the harmonic amplitude which can be resolved by the minimum energy of the system and is set according to the requirements of the system. The simulation sets the amplitude threshold to 0.001.
A fifth step of determining the three maximum spectral lines on the signal X (k Δ f) by setting k m Is the spectral line at the target frequency point, k 1 Is the spectral line with the maximum amplitude near the target frequency point, k 2 And k 3 Are each k 1 The left and right spectral lines have k in the three spectral line interpolation algorithm 1 ≠k m ，k 1 ＝k 2 +1＝k 3 -1；
Sixthly, determining the amplitudes of the three spectral lines, and sequentially naming the three spectral lines as y 1 ，y 2 ，y 3 ，y 1 ＝|x(k 1 Δf)|，y 2 ＝|x(k 2 Δf)|，y 3 ＝|x(k 3 Δf)|。
Step seven, setting variable alpha = k m -k 2 Alpha is more than or equal to-0.5 and less than or equal to 0.5, and a variable beta is present,
when N is larger, the formula f m ＝k m Δf＝(k 1 + α) Δ f is denoted β = g (α), the inverse of which is α = g -1 (beta). Thus determining the correction formula of the frequency as f m ＝k m Δf＝(k 1 +α)Δf。
Eighthly, determining an amplitude correction formula:
when N is larger, the formula amplitude correction formula can be expressed as A m ＝N -1 (y 2 +2y 1 +y 3 )h(α)；
Wherein h (α) is a polynomial approximation and has:
determining a phase correction formula:
ninth, finally obtaining parameters after three spectral line interpolation through a correction formula, wherein the parameters comprise frequency, amplitude and phase,
step ten, obtaining fitting signals through the parameters after the three spectral line interpolation,
obtaining a new signal x 'by fitting a signal calculation' m (n)，x' m (n)＝x(n)-x m (n)；
The tenth step is to judge a new signal x' m (n) is less than a signal amplitude threshold.
If not, let x (n) = x' m (n), to x' m And (n) performing iteration in a mode of repeating the second step and the tenth step.
If yes, outputting x' m (n)；
S6, new signal x' m (n) error analysis was performed. And acquiring the precision of the conventional window function interpolation algorithm and comparing the precision with the error obtained in the step S6.
The results of comparing the error analysis of the simulation are shown in tables 2 to 4, wherein D is fi Representing the relative error of the frequency measurement; d Ai Representing the relative error of the amplitude measurement;
indicating the relative error of the initial phase measurement.
TABLE 2 frequency relative error between conventional and harmonic component nulling
TABLE 3 amplitude relative error for conventional and harmonic component nulling methods
TABLE 4 phase relative error between conventional and harmonic component nulling
Therefore, when inter-harmonics occur, the result is wrong because the common interpolation algorithm can only analyze an integer number of harmonics, and the windowed interpolation based on the harmonic component zeroing can also keep high-precision analysis. The amplitude precision of the windowing interpolation based on harmonic component zero setting is improved by 2-3 orders of magnitude in the analysis of even harmonic and weak signals, and is improved by 3-4 orders of magnitude in the phase analysis. As can be seen from the simulation results in tables 2-4, the calculation results are generally better than the conventional window function spectral line interpolation algorithm.
Example two
The generalized harmonic analysis device based on harmonic component zeroing comprises an acquisition module, a windowing processing module, an FFT analysis module, an input module, a three-spectral-line correction module, a calculation module, a fitting calculation module, a judgment module and an error analysis module.
It should be noted that the modules in this embodiment may be a plurality of independent processing chips, or may be a plurality of processing modules in the same processing chip, and the following functions are implemented by the preloaded programs.
The acquisition module is used for acquiring a discrete grid signal x (n),
where m is the harmonic order, H is the highest harmonic order, A m Is the amplitude of the m-th harmonic,
is the phase of the m-th harmonic, f 0 Is the fundamental frequency, f s Is the sampling frequency, n is the nth sampling point;
the windowing processing module is used for carrying out windowing w (n) processing on the power grid signal x (n) and obtaining a windowed signal x w (n)，
Wherein N is the number of sampling points;
FFT analysis module for windowing signal x w (n) performing FFT transformation, analyzing the m-th harmonic,a signal X (k deltaf) is obtained,
wherein Δ f = f s N is the frequency resolution, W (-) is the spectral function of a given window function,
is the window function width, j is the imaginary part, k is the harmonic number;
the input module is used for setting a signal amplitude threshold value;
the three-spectral-line correction module is used for determining three maximum spectral lines on the signal X (k delta f) and determining the amplitudes of the three spectral lines, which are named as y in sequence 1 ，y 2 ，y 3 And determining the variables
And determining a three spectral line correction formula
The calculation module is used for obtaining parameters after the three spectral line interpolation through a correction formula, wherein the parameters comprise frequency, amplitude and phase,
the fitting calculation module is used for obtaining fitting signals through the parameters after the three-spectral-line interpolation,
and calculating to obtain a new signal x' m (n)，x' m (n)＝x(n)-x m (n)；
The judging module is used for judging a new signal x' m (n) is smaller than the signal amplitude threshold value, if not, x (n) = x' m (n), and iterating until the iteration is input into a three-spectral-line correction module, a calculation module and a fitting calculation module; if yes, outputting x' m (n)；
The error analysis module is used for comparing the new signal x' m (n) performing error analysis.
And signal transmission is realized among the modules through an inter-chip circuit or an intra-chip circuit.
The FFT analysis module comprises an FFT module and an analysis module.
FFT module for windowing signal x w (n) performing an FFT transform to obtain a windowed FFT spectrum:
the analysis module is used for neglecting the negative frequency point spectrum peak and analyzing and obtaining the m-th harmonic wave
The three spectral line correction modules comprise a first setting module, a second setting module, a first correction module, a second correction module, a third correction module and a spectral line amplitude calculation module.
The first setting module is used for setting k m Is the spectral line at the target frequency point, k 1 Is the spectral line with the maximum amplitude near the target frequency point, k 2 And k 3 Are each k 1 The left and right spectral lines have k in the three spectral line interpolation algorithm 1 ≠k m ，k 1 ＝k 2 +1＝k 3 -1；
The spectral line amplitude calculation module is used for obtaining the amplitude of the spectral line y 1 ＝|x(k 1 Δf)|，y 2 ＝|x(k 2 Δf)|，y 3 ＝|x(k 3 Δf)|；
The second setting module is used for setting the variable alpha = k m -k 2 Then-0.5. Ltoreq. Alpha. Ltoreq.0.5 with the variables
The first correction module is configured to determine a frequency correction formula: f. of m ＝k m Δf＝(k 1 +α)Δf；
The second correction module is configured to determine an amplitude correction formula:
the third correction module is configured to determine a phase correction formula:
EXAMPLE III
A generalized harmonic analysis terminal based on harmonic component zeroing comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the computer program to realize the steps of the generalized harmonic analysis method based on harmonic component zeroing.
The memory may be used to store software programs and modules, and the processor may execute various functional applications of the terminal and data processing by operating the software programs and modules stored in the memory. The memory may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an execution program required for at least one function, and the like.
The storage data area may store data created according to the use of the terminal, and the like. Further, the memory may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.
A computer-readable storage medium, in which a computer program is stored, which computer program, when being executed by a processor, carries out the steps of a generalized harmonic analysis method based on harmonic component zeroing as described above.
Without loss of generality, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instruction data structures, program modules or other data. Computer storage media includes RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology, CD-ROM, DVD, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices. Of course, those skilled in the art will appreciate that computer storage media is not limited to the foregoing. The system memory and mass storage devices described above may be collectively referred to as memory.
In the description herein, reference to the description of the terms "one embodiment/mode," "some embodiments/modes," "example," "specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/mode or example is included in at least one embodiment/mode or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to be the same embodiment/mode or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/aspects or examples and features of the various embodiments/aspects or examples described in this specification can be combined and combined by one skilled in the art without conflicting therewith.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specified otherwise.
It will be understood by those skilled in the art that the foregoing embodiments are merely for clarity of description and are not intended to limit the scope of the invention. Other variations or modifications may occur to those skilled in the art, which are based on the above-described invention, and which are still within the scope of the invention.
Claims (10)
1. A generalized harmonic analysis method based on harmonic component zeroing is characterized by comprising the following steps:
s1, obtaining a discrete power grid signal x (n),
where m is the harmonic order, H is the highest harmonic order, A m Is the amplitude of the m-th harmonic,
is the phase of the m-th harmonic, f 0 Is the fundamental frequency, f s Is the sampling frequency, n is the nth sampling point;
windowing w (n) processing is carried out on the power grid signal x (n), and a windowed signal x after windowing is obtained w (n)，
Wherein N is the number of sampling points;
for the windowed signal x w (n) performing FFT transformation and analyzing the m-th harmonic to obtain a signal X (k delta f),
wherein Δ f = f s where/N is the frequency resolution, W (-) is the spectral function of a given window function,
is the window function width, j is the imaginary part, k is the harmonic number;
s2, setting a signal amplitude threshold value;
s3, determining three maximum spectral lines on the signal X (k delta f), determining the amplitudes of the three spectral lines, and sequentially naming the three spectral lines as y 1 ，y 2 ，y 3 And determining the variables
And determining a three spectral line correction formula
Obtaining parameters after three spectral line interpolation through a correction formula, wherein the parameters comprise frequency, amplitude and phase,
s4, obtaining a fitting signal through the parameters subjected to the three-spectral-line interpolation,
calculating to obtain a new signal x' m (n)，x' m (n)＝x(n)-x m (n)；
S5, judging a new signal x' m (n) is smaller than the signal amplitude threshold value, if not, x (n) = x' m (n), and repeating steps S1-S4; if yes, outputting x' m (n)；
S6, for new signal x' m (n) error analysis was performed.
2. The generalized harmonic analysis method based on harmonic component nulling of claim 1, wherein the grid harmonic signal is sampled by a front-end transformer and a sampling circuit to obtain a discrete grid signal, the grid harmonic signal being
And t is time, and the power grid harmonic signals comprise voltage signals and current signals.
3. The generalized harmonic analysis method based on harmonic component nulling according to claim 1, wherein the specific method for obtaining the signal X (k Δ f) is:
for the windowed signal x w (n) performing FFT to obtain a windowed FFT spectrum:
ignoring the spectrum peak of the negative frequency point, and obtaining the m-th harmonic analysis
4. The generalized harmonic analysis method based on harmonic component nulling of claim 1, wherein the signal amplitude threshold is a system minimum-energy-resolved harmonic amplitude set according to system requirements.
5. The generalized harmonic analysis method based on harmonic component nulling according to claim 1, wherein the specific method of the three-line interpolation comprises:
setting k m Is the spectral line at the target frequency point, k 1 Is the spectral line with the maximum amplitude near the target frequency point, k 2 And k 3 Are each k 1 The left and right spectral lines have k in the three spectral line interpolation algorithm 1 ≠k m ，k 1 ＝k 2 +1＝k 3 -1；
Obtaining the amplitude, y, of the spectral line 1 ＝|x(k 1 Δf)|，y 2 ＝|x(k 2 Δf)|，y 3 ＝|x(k 3 Δf)|；
Set variable α = k m -k 2 If-0.5. Ltoreq. Alpha. Is not less than 0.5, there is a variable
Determining a frequency correction formula: f. of m ＝k m Δf＝(k 1 +α)Δf；
Determining an amplitude correction formula:
determining a phase correction formula:
6. the generalized harmonic analysis method based on harmonic component nulling of claim 1, wherein performing error analysis further comprises: and acquiring the precision of the conventional window function interpolation algorithm and comparing the precision with the error obtained in the step S6.
7. A generalized harmonic analysis apparatus based on harmonic component nulling, comprising:
an acquisition module for acquiring a discrete grid signal x (n),
where m is the harmonic order, H is the highest harmonic order, A m Is the amplitude of the m-th harmonic,
is the phase of the m-th harmonic, f 0 Is the fundamental frequency, f s Is the sampling frequency, n is the nth sampling point;
a windowing processing module for performing windowing w (n) processing on the power grid signal x (n) and obtaining a windowed signal x w (n)，
Wherein N is the number of sampling points;
FFT analysis module for windowing a windowed signal x w (n) performing FFT transformation and analyzing the m-th harmonic to obtain a signal X (k delta f),
wherein Δ f = f s where/N is the frequency resolution, W (-) is the spectral function of a given window function,
is the window function width, j is the imaginary part, k is the harmonic number;
an input module for setting a signal amplitude threshold;
a three-spectral-line correction module for determining the three largest spectral lines on the signal X (k Δ f) and determining the amplitudes of the three spectral lines, in turn named y 1 ，y 2 ，y 3 And determining the variables
And determining a three spectral line correction formula
A calculation module for obtaining parameters including frequency, amplitude and phase after the three spectral line interpolation through a correction formula,
a fitting calculation module for obtaining a fitting signal through the parameters after the three-spectral-line interpolation,
and calculating to obtain a new signal x' m (n)，x' m (n)＝x(n)-x m (n)；
A judging module for judging the new signal x' m If the (n) is smaller than the signal amplitude threshold value, if not, making x (n) = x' m (n), and iterating until the iteration is input into a three-spectral-line correction module, a calculation module and a fitting calculation module; if yes, outputting x' m (n)；
An error analysis module for comparing the new signal x' m (n) performing error analysis.
8. The generalized harmonic analysis apparatus according to claim 7, wherein the FFT analysis module comprises:
FFT module for windowingSignal x w (n) performing FFT to obtain a windowed FFT spectrum:
an analysis module for neglecting the negative frequency point spectrum peak and obtaining the m-th harmonic wave by analysis
9. The generalized harmonic analysis apparatus according to claim 7, wherein the three-spectral-line modification module comprises:
a first setting module for setting k m Is the spectral line at the target frequency point, k 1 Is the spectral line with the maximum amplitude near the target frequency point, k 2 And k 3 Are each k 1 The left and right spectral lines have k in the three spectral line interpolation algorithm 1 ≠k m ，k 1 ＝k 2 +1＝k 3 -1；
A spectral line amplitude calculation module for obtaining the amplitude, y, of the spectral line 1 ＝|x(k 1 Δf)|，y 2 ＝|x(k 2 Δf)|，y 3 ＝|x(k 3 Δf)|；
A second setting module for setting the variable α = k m -k 2 Then-0.5. Ltoreq. Alpha. Ltoreq.0.5 with the variables
A first correction module to determine a frequency correction formula: f. of m ＝k m Δf＝(k 1 +α)Δf；
A second correction module for determining an amplitude correction formula:
a third correction module for determining a phase correction equation:
10. a computer-readable storage medium, in which a computer program is stored, which, when being executed by a processor, carries out the steps of a method for generalized harmonic analysis based on harmonic component nulling as defined in any one of claims 1 to 6.
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