Power grid broadband signal adaptive measurement method, device and system

Abstract

The present invention discloses an adaptive measurement method, device and system for broadband signals of a power grid, the method comprising: obtaining a signal spectrum and a main lobe interference condition of a broadband signal of a power grid; according to the main lobe interference condition of the signal, adaptively using a dual-spectrum interpolation algorithm or a complex modulation refinement spectrum analysis method to estimate signal parameters of the signal spectrum, and obtaining all parameters of the broadband signal of the power grid. The present invention uses the phase characteristics of the spectrum lines of the signal spectrum to adaptively determine the main lobe interference of the signal, uses a complex modulation refinement spectrum analysis method to estimate parameters for the signal spectrum with main lobe interference, and uses a dual-spectrum interpolation algorithm to estimate the signal spectrum without main lobe interference. The present invention effectively realizes high-precision adaptive measurement of harmonics within a wide frequency range.

Description

Technical Field

[0001] The present invention belongs to the technical field of broadband signal measurement in electric power systems, and in particular relates to a method, device and system for adaptively measuring broadband signals in power grids. Background Art

[0002] Real-time and accurate measurement of each component of the power grid signal is an important guarantee for the safe and stable operation of the power grid. However, the existing synchronous phasor measurement unit (PMU), power quality monitoring device and measurement algorithm are mostly aimed at the measurement of power frequency and harmonics below 20, and cannot fully monitor the power grid signal in the wide frequency range of 0 to 2.5kHz. In addition, the existing measurement algorithms are mostly limited to the measurement of power frequency and harmonic signals, and the harmonic frequency resolution of the power quality detection device is only 5Hz, which is difficult to meet the resolution requirements of all signals in the wide frequency range.

[0003] In terms of measurement algorithms for harmonic and interharmonic signals, Fast Fourier Transform (FFT) is the most widely used type of spectrum analysis method. Among them, the windowed interpolation correction measurement algorithm has the advantages of small computational complexity and stable measurement accuracy. However, when the spectral lines used in the interpolation correction are affected by spectral line interference, the correction accuracy will be greatly reduced. This type of algorithm cannot effectively measure harmonics and interharmonics with similar frequencies while ensuring the real-time performance of the algorithm.

[0004] ZoomFFT can perform frequency domain analysis on a specific frequency range with high resolution and measure the components of signals with similar frequencies, but it cannot achieve comprehensive measurement in the wide frequency range of 0 to 2.5 kHz. Modern spectrum estimation algorithms based on multiple signal classification (MUSIC) and rotationally invariant parameter estimation (ESPRIT) have the characteristics of super-resolution, but the amount of calculation is large and the source number estimation process is easily affected by noise, resulting in a sharp drop in algorithm accuracy. Summary of the invention

[0005] In view of the above problems, the present invention proposes a method, device and system for adaptively measuring power grid broadband signals, which can realize high-precision adaptive measurement of power grid harmonics and interharmonics with similar frequencies within a broadband range.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides a method for adaptively measuring a broadband signal of a power grid, comprising:

[0008] Obtain the signal spectrum and main lobe interference of the power grid broadband signal;

[0009] According to the main lobe interference of the signal, a dual spectrum line interpolation algorithm or a complex modulation refinement spectrum analysis method is adaptively adopted to estimate the signal parameters of the signal spectrum to obtain all parameters of the power grid broadband signal.

[0010] Optionally, acquiring a signal spectrum of a power grid broadband signal includes:

[0011] Sampling the power grid broadband signal at N points to obtain a sampling sequence;

[0012] A 4-term 5th-order Nuttall window is added to the sampling sequence, and a discrete Fourier transform is performed to obtain the signal spectrum.

[0013] Optionally, the method for acquiring the signal main lobe interference situation includes:

[0014] Sample the signal spectrum to obtain a digital spectrum;

[0015] When it is determined based on the digital spectrum that the spectrum lines in the main lobe of the digital spectrum are not affected by signal components of other frequencies, the signal main lobe interference situation is obtained using the spectrum line phase characteristics.

[0016] Optionally, when the absolute value of the phase difference between adjacent spectral lines in the main lobe of the digital spectrum is π, it is determined that the spectral lines in the main lobe of the digital spectrum are not affected by signal components of other frequencies.

[0017] Optionally, the signal main lobe interference condition includes that there is no interference in the spectral lines in the main lobe or that there is interference in the spectral lines in the main lobe; and obtaining the signal main lobe interference condition by using the spectral line phase characteristics specifically includes:

[0018] The maximum value of the difference between the phase difference between adjacent spectral lines in each main lobe of the digital spectrum and π Compared with the threshold ε;

[0019] When satisfied It is considered that there is interference in the spectral lines in the main lobe:

[0020] When satisfied It is considered that there is no interference in the spectral lines in the main lobe.

[0021] Optionally, according to the main lobe interference of the signal, a dual-spectrum interpolation algorithm or a complex modulation refinement spectrum analysis method is adaptively used to estimate signal parameters of the signal spectrum, specifically including:

[0022] When there is no interference in the spectrum line of the main lobe, the double spectrum line interpolation correction algorithm based on the 4-term 5th-order Nuttall window is used to estimate the parameters of the signal spectrum without main lobe interference;

[0023] When there is interference in the spectrum lines in the main lobe, the complex modulation refinement spectrum analysis method is used to estimate the parameters of the signal spectrum with main lobe interference.

[0024] In a second aspect, the present invention provides a power grid broadband signal adaptive measurement device, comprising:

[0025] A signal processing module is used to obtain the signal spectrum and main lobe interference of the power grid broadband signal;

[0026] The parameter estimation module is used to adaptively use a dual-spectrum interpolation algorithm or a complex modulation refinement spectrum analysis method to estimate the signal parameters of the signal spectrum according to the main lobe interference of the signal, so as to obtain all parameters of the power grid broadband signal.

[0027] In a third aspect, the present invention provides a power grid broadband signal adaptive measurement system, including a storage medium and a processor;

[0028] The storage medium is used to store instructions;

[0029] The processor is configured to operate according to the instructions to execute the steps of the method according to any one of the first aspects.

[0030] In a fourth aspect, the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any one of the methods described in the first aspect when executing the computer program.

[0031] In a fifth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any one of the methods described in the first aspect.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention firstly utilizes the phase characteristics of the signal spectrum to determine whether there is mainlobe interference. According to the determination result, the present invention adaptively adopts a dual-spectrum interpolation correction algorithm with small computational complexity and meeting the requirements of harmonic measurement, as well as a complex modulation refinement spectrum analysis method with higher resolution and meeting the requirements of the measurement of interharmonics with similar frequencies and low-amplitude high-order harmonics. The present invention can effectively realize high-precision adaptive measurement of harmonics and interharmonics with similar frequencies in the range of 0 to 2.5 kHz. The higher measurement accuracy and lower computational cost enable the method to meet the measurement requirements of broadband power grids. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings, wherein:

[0035] Figure 1 It is a schematic diagram of the method flow of the present invention;

[0036] FIG. 2( a ) is a diagram showing a power grid signal measurement result and a relative error diagram of the method of the present invention;

[0037] FIG2( b ) is a second diagram of the power grid signal measurement result and relative error of the method of the present invention;

[0038] FIG. 2( c ) is a third diagram of the power grid signal measurement result and relative error of the method of the present invention;

[0039] Figure 3 The waveform diagram of the three-phase voltage signal actually measured in the power grid within 10 fundamental wave cycles. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of protection of the present invention.

[0041] The application principle of the present invention is described in detail below in conjunction with the accompanying drawings.

[0042] Example 1

[0043] like Figure 1 As shown, the present invention provides a method for adaptively measuring broadband signals of a power grid, and the specific steps are as follows:

[0044] Obtain the signal spectrum and main lobe interference of the power grid broadband signal;

[0045] According to the main lobe interference of the signal, a dual-spectrum interpolation algorithm or a complex modulation refinement spectrum analysis method (ZoomFFT algorithm) is adaptively used to estimate the signal parameters of the signal spectrum to obtain all parameters of the power grid broadband signal.

[0046] In a specific implementation of the embodiment of the present invention, the method for acquiring the signal spectrum includes:

[0047] With sampling frequency f s The broadband signal of the power grid is sampled at N points to obtain a sampling sequence; the expression of the broadband signal of the power grid is:

[0048]

[0049] Among them, A m 、f m , are the amplitude, frequency and phase of the mth signal component in the power grid broadband signal, respectively, and M is the number of signal components in the power grid broadband signal;

[0050] Add 4 5th-order Nuttall windows to the sampling sequence and perform discrete Fourier transform to obtain the signal spectrum; the expression of the signal spectrum is:

[0051]

[0052] Among them, X(e jw ) is the signal spectrum, W4(ω) is the amplitude spectrum of the 4-term 5th-order Nuttall window, ω m f m The digital angular frequency.

[0053] In a specific implementation of the embodiment of the present invention, the method for acquiring the signal main lobe interference situation includes:

[0054] The signal spectrum X(e) is analyzed at intervals of 2π / N. jw ) is sampled to obtain a digital spectrum, that is, to obtain a digital frequency representation of the signal spectrum, specifically:

[0055]

[0056] Where, λ=Nω / 2π, λ m =Nω m / 2π=Nf m / f s , W R (λ) = sin(λπ) / sin(λπ / N) is the rectangular window amplitude spectrum expressed in digital frequency;

[0057] When it is determined based on the digital spectrum that the spectrum lines in the main lobe of the digital spectrum are not affected by signal components of other frequencies, the signal main lobe interference situation is obtained using the spectrum line phase characteristics;

[0058] In the specific implementation process, when the absolute value of the phase difference between adjacent spectral lines in the main lobe of the digital spectrum is π, it is determined that the spectral lines in the main lobe of the digital spectrum are not affected by signal components of other frequencies. The calculation formula for the absolute value of the phase difference between adjacent spectral lines is:

[0059]

[0060] Wherein, X(·) is the amplitude spectrum line value, i is the peak spectrum line number in the main lobe, k is the number of the difference between the phase difference between each spectrum line and π, k = 1, 2, 3, 4.

[0061] The signal main lobe interference condition includes that the spectral lines in the main lobe do not have interference or that the spectral lines in the main lobe have interference; the obtaining of the signal main lobe interference condition by using the spectral line phase characteristics specifically includes:

[0062] The maximum value of the difference between the phase difference between adjacent spectral lines in each main lobe of the digital spectrum and π Compared with the threshold ε;

[0063] When satisfied It is considered that the spectrum lines in the main lobe are interfered (that is, there are only multiple signal components in this spectrum):

[0064] When satisfied It is considered that there is no interference in the spectrum line in the main lobe (that is, there is only one signal component in this spectrum).

[0065] In a specific implementation of the embodiment of the present invention, the method of adaptively using a dual-spectrum interpolation algorithm or a complex modulation refinement spectrum analysis method to estimate signal parameters of the signal spectrum according to the main lobe interference of the signal specifically includes:

[0066] When there is interference in the spectral lines in the main lobe, a dual-spectral line interpolation correction algorithm based on a 4-term 5th-order Nuttall window is used to estimate the parameters of the signal spectrum with main lobe interference.

[0067] When there is no interference in the spectrum lines in the main lobe, the complex modulation refinement spectrum analysis method is used to estimate the parameters of the signal spectrum without main lobe interference.

[0068] The method of using a dual-line interpolation correction algorithm based on a 4-term 5th-order Nuttall window to perform parameter estimation on a signal spectrum without main lobe interference specifically includes the following steps:

[0069] Calculate the spectral line amplitude ratio β of any two adjacent frequency points m , the spectral line amplitude ratio β m The calculation formula is:

[0070]

[0071] Combined with the spectral line amplitude ratio β m , calculate the signal frequency f m The corresponding digital frequency position λ m , the digital frequency position λ m The calculation formula is:

[0072] λ m =k m +δ m

[0073] Among them, k m is a positive integer sampling point, δ m is the interpolation coefficient, and δ m ∈[0,1);

[0074] The parameters of the signal spectrum are estimated according to the bispectral interpolation correction algorithm of the four-term fifth-order Nuttall window; the frequency, amplitude and phase parameter estimation formulas of the bispectral interpolation correction algorithm of the four-term fifth-order Nuttall window are respectively:

[0075]

[0076] Among them, f m , A m , are the frequency, amplitude and phase of the mth signal component, k m is a positive integer sampling point, δ m is the interpolation coefficient, f s is the sampling frequency, and N is the number of sampling points.

[0077] The method of using complex modulation refined spectrum analysis to estimate parameters of the signal spectrum with main lobe interference specifically includes:

[0078] After windowing and sampling the broadband signal of the power grid, N ZFFT =DN points in the time domain sequence, D is the refinement multiple, and the time domain sequence is multiplied by the unit rotation factor Perform complex modulation frequency shift to form a frequency f corresponding to the spectrum line with main lobe interference in the spectrum i is the new signal y(n) with frequency zero;

[0079] After the new signal y(n) is subjected to FFT transformation, the obtained frequency domain sequence (i.e., spectrum) is subjected to low-pass digital filtering;

[0080] The frequency domain sequence after low-pass digital filtering is subjected to IFFT of length DN. After obtaining the time domain sequence, it is resampled with a sampling interval of D and a sampling frequency of f. s / D;

[0081] Perform FFT on the N-point time domain sequence obtained after resampling, and rearrange it by moving the zero-frequency component to the center of the sequence. At this time, the frequency resolution is (f s / D) / N=f s / DN;

[0082] According to the rearranged FFT results, the broadband signal of the power grid can be obtained at a frequency of f i Centered on the frequency range f s / D, and realize the parameter estimation of the signal spectrum within this frequency range. The frequency, amplitude and phase parameter estimation formulas of the complex modulation refined spectrum analysis method are respectively:

[0083]

[0084] A=|X(k i )|

[0085]

[0086] Among them, f, A, are the frequency, amplitude and phase of the signal component corresponding to the frequency spectrum line with main lobe interference, k i is the digital frequency point where the main lobe interference spectrum exists, f s is the sampling frequency, N ZFFT is the number of sampling points of complex modulation spectrum analysis, D is the refinement factor, X(k i ) is the signal spectrum expressed in digital frequency.

[0087] The application of the method in the embodiment of the present invention is described in detail below in conjunction with a specific implementation manner.

[0088] (1) First, it is necessary to analyze and determine the threshold ε for judging the main lobe interference: Since the value of the threshold ε directly affects the adaptability of the measurement method in the embodiment of the present invention, a smaller value will lead to misjudgment of the main lobe interference, while a larger value will cause missed judgment, making it impossible to effectively estimate the signal parameters and the method ineffective. After simulating and traversing signal components with different amplitude ratios and frequency differences under different signal-to-noise ratios, on the premise that the signal components (such as components with similar frequencies or low amplitudes) that cannot be effectively estimated by the spectral line interpolation method can be effectively identified, the introduction of unnecessary calculations is avoided as much as possible, and the threshold is set to ε = 1.4.

[0089] (2) The method proposed in the present invention is used to measure the broadband signal of the power grid and construct a simulation signal:

[0090] Combined with the characteristics of broadband signals in actual power grids, the signal-to-noise ratio (SNR) of a power grid signal containing fundamental wave, harmonics and interharmonics is set to 60 dB. The parameter setting values ​​are shown in Table 1.

[0091] Table 1 Simulation signal parameter setting values

[0092]

[0093]

[0094] Set the sampling frequency to f s =6.4kHz, according to the International Electrotechnical Commission standard IEC 61000-4-30, the sampling signal spectrum analysis time window is set to 10 fundamental wave cycles, that is, the number of sampling points N≈1280. The refinement multiple D of the ZoomFFT is set to 50, and the number of sampling points N ZFFT =12800.

[0095] Considering that the signal component with lower amplitude is easily affected by background noise or other signal component spectrum leakage and main lobe interference occurs, the signal is simulated and measured 100 times and the measurement results are averaged to ensure the reliability of the simulation results. The simulation measurement results are shown in Table 2. Figure 2(a)-Figure 2(c) As shown, the error bar size is the error standard deviation of each signal component parameter, that is, ±σ, which is used to indicate the accuracy stability of the method proposed in the present invention.

[0096] Table 2 Measurement results of power grid broadband signal

[0097]

[0098] The simulation results show that the present invention effectively realizes the adaptive measurement of the signal, wherein the ZoomFFT algorithm estimates the parameters of the fundamental wave and its nearby interharmonics and interharmonics with a frequency difference of only 1 Hz, and the dual-spectrum interpolation correction algorithm based on the 4-term 5th-order Nuttall window measures the harmonic components that do not produce main lobe interference. In addition, although there are no other signal components near the 35th and 49th harmonics, their low amplitudes make them susceptible to spectrum leakage and background noise and produce main lobe interference. Therefore, in the simulation process, both algorithms have estimated the parameters of this component.

[0099] Compared with the dual-line interpolation correction algorithm based on the 4-term 5th-order Nuttall window, the overall measurement results of the ZoomFFT algorithm are more stable, with smaller error fluctuations, higher frequency estimation accuracy, and accurate estimation of frequency parameters. However, the amplitude estimation accuracy is slightly lower than the latter, which also leads to larger fluctuations in the parameter estimation error of high-order harmonics. In terms of phase estimation accuracy, the two algorithms are basically equivalent. In summary, the overall accuracy of the method proposed in the present invention is high, the stability is good, and the relative frequency error is less than 7×10 -5 , the amplitude error is on the order of 10 -4 ~10 -3 , the phase error does not exceed 1.6×10 -2 .

[0100] (3) The method of the present invention is used to measure the actual voltage signal of the power grid:

[0101] The method proposed in the present invention is used to record the 220kV bus three-phase voltage data of the Houshuiquan wind farm of CRRC Wind Power (such as Figure 3 The voltage ratio is 220 kV / 100 V. The recorded data is obtained by continuous recording of the synchronized phasor measurement device (SMU-2ME) installed on site. The sampling frequency is 6.4 kHz. The initial data length of the method is N = 1280. If there is main lobe interference, it is increased to N = 12800 to meet the needs of ZoomFFT operation. The main lobe interference judgment threshold is still ε = 1.4. The parameter estimation results are shown in Table 3.

[0102] Table 3 Measured voltage signal measurement results

[0103]

[0104] It can be seen from the results that the present invention effectively estimates the parameters of each signal. In terms of frequency, the fundamental frequency of the voltage signal has no frequency offset and no interharmonics, but there are multiple low-amplitude harmonic components up to the 13th order in the signal. In terms of amplitude, the mean value of the fundamental frequency phase voltage is 57.734V, and the corresponding line voltage is 99.998V, which is in line with the actual voltage transformation ratio, and the amplitude estimation accuracy is relatively high. In addition, there is a certain degree of imbalance between the three phases, such as the 13th harmonic only in phase A and phase B. Such harmonics may not exist in other phases or the amplitude is less than 0.1V. In terms of phase, the phase estimation result is verified by whether the phase difference between the phases is 120°:

[0105]

[0106] in, They are the three-phase phases, θ A ,θ B ,θ C is the phase deviation, then:

[0107]

[0108] in, The imbalance degree is used to characterize the imbalance degree of each phase under the actual operation of the power grid. Under the ideal operation of the power grid, e · is the phase estimation error, that is, the method error introduced by the measurement method, then:

[0109]

[0110] Since the recorded data has a black box property and the phase is a relative value, it is considered that the sum of the absolute values ​​of the unbalance of each harmonic component is a constant, that is, Then, the mean of the absolute phase deviation can be used to roughly measure the phase estimation error of the measurement method:

[0111]

[0112] At this time, the phase estimation results of the harmonic components that are stably present in the three phases and the average values ​​of their absolute phase deviations are shown in Table 4.

[0113] Table 4 Phase estimation results and mean of absolute phase deviation

[0114]

[0115] On the one hand, it can be seen that the three-phase phases in the voltage signal are relatively balanced, and the phase difference between the power frequency phases is basically 120°. On the other hand, in actual situations, odd harmonics in the power grid signal generally have a certain degree of three-phase imbalance. The degree of imbalance is related to factors such as the harmonic source and amplitude. At this time, if we assume that the method error e · The unbalance of each harmonic is consistent with the actual situation because it fluctuates slightly around a fixed value due to the high and low amplitude of the component. In summary, it can be considered that the measurement method proposed in the present invention achieves phase estimation with high accuracy.

[0116] Example 2

[0117] Based on the same inventive concept as that of Embodiment 1, an embodiment of the present invention provides a power grid broadband signal adaptive measurement device, comprising:

[0118] A signal processing module is used to obtain the signal spectrum and main lobe interference of the power grid broadband signal;

[0119] The parameter estimation module is used to adaptively use a dual-spectrum interpolation algorithm or a complex modulation refinement spectrum analysis method to estimate the signal parameters of the signal spectrum according to the main lobe interference of the signal, so as to obtain all parameters of the power grid broadband signal.

[0120] The rest are the same as in Example 1.

[0121] Example 3

[0122] An embodiment of the present invention provides a power grid broadband signal adaptive measurement system, including a storage medium and a processor;

[0123] The storage medium is used to store instructions;

[0124] The processor is used to operate according to the instructions to execute the steps of the method according to any one of Embodiment 1.

[0125] Example 4

[0126] In an embodiment of the present invention, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any one of the methods described in Embodiment 1 when executing the computer program.

[0127] Example 5

[0128] In an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, characterized in that when the computer program is executed by a processor, the steps of the method described in any one of Embodiment 1 are implemented.

[0129] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0130] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0131] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0132] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for adaptively measuring broadband signals of a power grid, characterized in that: include: Obtain the signal spectrum and main lobe interference of the power grid broadband signal; According to the main lobe interference of the signal, a dual spectrum line interpolation algorithm or a complex modulation refinement spectrum analysis method is adaptively used to estimate the signal parameters of the signal spectrum to obtain all parameters of the power grid broadband signal; The method for acquiring the signal main lobe interference situation includes: Sample the signal spectrum to obtain a digital spectrum; When it is determined based on the digital spectrum that the spectrum lines in the main lobe of the digital spectrum are not affected by signal components of other frequencies, the signal main lobe interference situation is obtained using the spectrum line phase characteristics; The signal main lobe interference condition includes that the spectral lines in the main lobe do not have interference or that the spectral lines in the main lobe have interference; the obtaining of the signal main lobe interference condition by using the spectral line phase characteristics specifically includes: The maximum value of the difference between the phase difference between adjacent spectral lines in each main lobe of the digital spectrum and π Compared with the threshold ε; When satisfied It is considered that there is interference in the spectral lines in the main lobe: When satisfied It is considered that there is no interference in the spectral lines in the main lobe; According to the main lobe interference of the signal, a dual spectrum line interpolation algorithm or a complex modulation refinement spectrum analysis method is adaptively used to estimate the signal parameters of the signal spectrum, specifically including: When there is no interference in the spectrum line of the main lobe, the double spectrum line interpolation correction algorithm based on the 4-term 5th-order Nuttall window is used to estimate the parameters of the signal spectrum without main lobe interference; When there is interference in the spectrum line of the main lobe, the complex modulation refinement spectrum analysis method is used to estimate the parameters of the signal spectrum with main lobe interference; ε=1.4; The method of using a dual-line interpolation correction algorithm based on a 4-term 5th-order Nuttall window to estimate the parameters of a signal spectrum without main lobe interference specifically includes the following steps: Calculate the spectral line amplitude ratio β of any two adjacent frequency points m , the spectral line amplitude ratio β m The calculation formula is: Combined with the spectral line amplitude ratio β m , calculate the signal frequency f m The corresponding digital frequency position λ m , the digital frequency position λ m The calculation formula is: l m =k m +d m Among them, k m is a positive integer sampling point, δ m is the interpolation coefficient, and δ m ∈[0,1); Based on the dual-line interpolation correction algorithm of the four-term fifth-order Nuttall window, the frequency, amplitude and phase parameters of the signal spectrum without main lobe interference are estimated. The estimation formulas of frequency, amplitude and phase parameters are: Among them, f m , A m , are the frequency, amplitude and phase of the mth signal component, k m is a positive integer sampling point, δ m is the interpolation coefficient, f s is the sampling frequency, and N is the number of sampling points.

2. The method for adaptively measuring broadband signals of a power grid according to claim 1, characterized in that: The obtaining of the signal spectrum of the power grid broadband signal comprises: Sampling the power grid broadband signal at N points to obtain a sampling sequence; A 4-term 5th-order Nuttall window is added to the sampling sequence, and a discrete Fourier transform is performed to obtain the signal spectrum.

3. A power grid broadband signal adaptive measurement device, characterized in that: include: A signal processing module is used to obtain the signal spectrum and main lobe interference of the power grid broadband signal; A parameter estimation module is used to adaptively use a dual spectrum interpolation algorithm or a complex modulation refinement spectrum analysis method to estimate the signal parameters of the signal spectrum according to the main lobe interference of the signal, so as to obtain all parameters of the power grid broadband signal; The method for acquiring the signal main lobe interference situation includes: Sample the signal spectrum to obtain a digital spectrum; When it is determined based on the digital spectrum that the spectrum lines in the main lobe of the digital spectrum are not affected by signal components of other frequencies, the signal main lobe interference situation is obtained using the spectrum line phase characteristics; The signal main lobe interference condition includes that the spectral lines in the main lobe do not have interference or that the spectral lines in the main lobe have interference; the obtaining of the signal main lobe interference condition by using the spectral line phase characteristics specifically includes: The maximum value of the difference between the phase difference between adjacent spectral lines in each main lobe of the digital spectrum and π Compared with the threshold ε; When satisfied It is considered that there is interference in the spectral lines in the main lobe: When satisfied It is considered that there is no interference in the spectral lines in the main lobe; According to the main lobe interference of the signal, a dual spectrum line interpolation algorithm or a complex modulation refinement spectrum analysis method is adaptively used to estimate the signal parameters of the signal spectrum, specifically including: When there is no interference in the spectrum line of the main lobe, the double spectrum line interpolation correction algorithm based on the 4-term 5th-order Nuttall window is used to estimate the parameters of the signal spectrum without main lobe interference; When there is interference in the spectrum line of the main lobe, the complex modulation refinement spectrum analysis method is used to estimate the parameters of the signal spectrum with main lobe interference; ε=1.4; The method of using a dual-line interpolation correction algorithm based on a 4-term 5th-order Nuttall window to estimate the parameters of a signal spectrum without main lobe interference specifically includes the following steps: Calculate the spectral line amplitude ratio β of any two adjacent frequency points m , the spectral line amplitude ratio β m The calculation formula is: Combined with the spectral line amplitude ratio β m , calculate the signal frequency f m The corresponding digital frequency position λ m , the digital frequency position λ m The calculation formula is: l m =k m +d m Among them, k m is a positive integer sampling point, δ m is the interpolation coefficient, and δ m ∈[0,1); Based on the dual-line interpolation correction algorithm of the four-term fifth-order Nuttall window, the frequency, amplitude and phase parameters of the signal spectrum without main lobe interference are estimated. The estimation formulas of frequency, amplitude and phase parameters are: Among them, f m , A m , are the frequency, amplitude and phase of the mth signal component, k m is a positive integer sampling point, δ m is the interpolation coefficient, f s is the sampling frequency, and N is the number of sampling points.

4. A power grid broadband signal adaptive measurement system, characterized in that: including storage media and processors; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the method according to any one of claims 1 to 2.

5. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 2 are implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 2 are implemented.

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