Power frequency interference filtering method and system for vibration signals and medium

Abstract

The invention relates to the technical field of signal processing, in particular to a power frequency interference filtering method and system for a vibration signal and a medium, and the method comprises the steps: carrying out the self-correlation operation of the vibration signal, and generating a self-correlation signal; windowing the autocorrelation signal to obtain a first windowed signal; performing fast Fourier transform on the first windowed signal to generate a first amplitude spectrum; according to the spectrum peak value adjacent to the first main lobe, the amplitude and the frequency of the power frequency signal are obtained through calculation; windowing the vibration signal to obtain a second windowing signal; performing fast Fourier transform on the second windowed signal to generate a second amplitude spectrum; the initial phase of the power frequency signal is obtained through calculation according to the spectrum peak value adjacent to the second main lobe; establishing an expression of the power frequency signal according to the amplitude, the frequency and the initial phase of the power frequency signal, and subtracting the power frequency signal from the vibration signal to obtain a vibration signal without power frequency interference; according to the invention, the power frequency interference in the vibration signal can be effectively filtered.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and particularly relates to a power frequency interference filtering method, system and medium for vibration signals. Background Art

[0002] Due to the complex on-site working environment, the power frequency interference of the power supply is coupled in the vibration signal of the steam turbine. If these signals are directly used without processing, it will lead to misjudgment of the actual operating state of the steam turbine.

[0003] Therefore, it is necessary to provide a solution that can filter out the power frequency interference in the vibration signal, obtain a true interference-free vibration signal, and avoid misjudgment of the vibration condition of the steam turbine. Summary of the Invention

[0004] The purpose of the present invention is to provide a power frequency interference filtering method, system and medium for vibration signals, which can effectively filter out the power frequency interference in the vibration signal by integrating the autocorrelation theory and the windowed interpolation method.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] On the one hand, an embodiment of the present invention provides a power frequency interference filtering method for vibration signals, and the method includes the following steps:

[0007] Obtain a vibration signal, perform autocorrelation operation on the vibration signal to generate an autocorrelation signal;

[0008] Perform windowing processing on the autocorrelation signal to obtain a first windowed signal; perform fast Fourier transform on the first windowed signal to generate a first amplitude spectrum;

[0009] Obtain a first main lobe according to the first amplitude spectrum, and calculate the amplitude and frequency of the power frequency signal according to the spectral peak values adjacent to the first main lobe;

[0010] Perform windowing processing on the vibration signal to obtain a second windowed signal; perform fast Fourier transform on the second windowed signal to generate a second amplitude spectrum;

[0011] Obtain a second main lobe according to the second amplitude spectrum, and calculate the initial phase of the power frequency signal according to the spectral peak values adjacent to the second main lobe;

[0012] Establish an expression of the power frequency signal according to the amplitude, frequency and initial phase of the power frequency signal, and subtract the power frequency signal from the vibration signal to obtain a vibration signal filtered from power frequency interference.

[0013] Preferably, the performing windowing processing on the autocorrelation signal to obtain a first windowed signal includes:

[0014] The autocorrelation signal is windowed using a Hanning window function to obtain a first windowed signal.

[0015] Preferably, calculating the amplitude and frequency of the power frequency signal based on the spectral peak adjacent to the first main lobe includes:

[0016] Determining a first interpolation coefficient based on the amplitudes of the spectral lines on both sides of the first main lobe;

[0017] Determining the frequency of the power frequency based on the frequency of the spectral line on one side of the first main lobe, the first interpolation coefficient, the total number of data points in the vibration signal, and the sampling interval;

[0018] Determining the amplitude of the power frequency based on the amplitude of the spectral line on one side of the first main lobe and the first interpolation coefficient, and calculating the amplitude of the vibration signal based on the amplitude of the power frequency.

[0019] Preferably, the calculation formula for the first interpolation coefficient is:

[0020]

[0021] where δ is the first interpolation coefficient, h m is the amplitude of the left spectral line on the main lobe of the power frequency spectrum, h m+1 is the amplitude of the right spectral line on the main lobe of the power frequency spectrum, and m is the data point number corresponding to the main lobe of the power frequency spectrum.

[0022] Preferably, the amplitude and frequency of the power frequency signal are calculated by the following formulas:

[0023]

[0024] where A is the amplitude of the power frequency, f0 is the frequency of the power frequency, f m is the frequency of the left spectral line on the first main lobe of the power frequency spectrum; h m is the amplitude of the left spectral line on the first main lobe of the power frequency spectrum; N is the total number of data points, and T is the sampling interval.

[0025] Preferably, windowing the vibration signal to obtain a second windowed signal includes:

[0026] Windowing the vibration signal using a Hanning window function and calculating to obtain a second windowed signal.

[0027] Preferably, calculating the initial phase of the power frequency signal based on the spectral peak adjacent to the second main lobe includes:

[0028] Determining a second interpolation coefficient based on the amplitudes of the spectral lines on both sides of the second main lobe;

[0029] Determining the initial phase of the power frequency signal based on the amplitude of the spectral line on one side of the second main lobe and the second interpolation coefficient.

[0030] Preferably, the expression of the power frequency signal is:

[0031] η(n) = A0 cos(2πf0n / N + θ0 / π·180);

[0032] where A0 is the amplitude of the vibration signal, f0 is the frequency of the power frequency, n is the number of the data point, and θ0 is the initial phase of the power frequency signal;

[0033] The initial phase of the power frequency signal is calculated by the following formula:

[0034] θ0 = phase(h′ m ) - π·δ′ - 0.5π;

[0035] where h′ m is the amplitude of the left spectral line on the second main lobe of the power frequency spectrum; phase(h′ m ) is the phase corresponding to h′ m , and δ′ is the second interpolation coefficient.

[0036] On the other hand, an embodiment of the present invention provides a power frequency interference filtering system for a vibration signal, and the system includes:

[0037] At least one processor;

[0038] At least one memory for storing at least one program;

[0039] When the at least one program is executed by the at least one processor, the at least one processor implements the method described in any one of the above.

[0040] On the other hand, an embodiment of the present invention provides a computer-readable storage medium, in which a program executable by a processor is stored, and characterized in that the program executable by the processor is used to execute the method described in any one of the above when executed by the processor.

[0041] The beneficial effects of the present invention are as follows: By performing autocorrelation operation on the vibration signal, an autocorrelation signal is generated; then, windowing processing is performed on the autocorrelation signal to obtain a first windowed signal; furthermore, fast Fourier transform is performed on the first windowed signal to generate a first amplitude spectrum; a first main lobe is obtained based on the first amplitude spectrum, and the amplitude and frequency of the power frequency signal are calculated according to the spectral peaks adjacent to the first main lobe; by performing windowing processing on the vibration signal, a second windowed signal is obtained; furthermore, fast Fourier transform is performed on the second windowed signal to generate a second amplitude spectrum; a second main lobe is obtained based on the second amplitude spectrum, and the initial phase of the power frequency signal is calculated according to the spectral peaks adjacent to the second main lobe; finally, an expression of the power frequency signal is established based on the amplitude, frequency, and initial phase of the power frequency signal, and the power frequency signal is subtracted from the vibration signal to obtain a vibration signal with power frequency interference filtered out. By integrating the autocorrelation theory and the windowing interpolation method, the present invention can effectively filter out the power frequency interference in the vibration signal, obtain a true interference-free vibration signal, and avoid misjudgment of the vibration condition of the steam turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0043] Figure 1a is a schematic diagram of the frequency spectrum of a notch filter in the related art;

[0044] Figure 1b is through Figure 1a is a schematic diagram of a mechanical vibration signal filtered by a corresponding filter;

[0045] Figure 2 is a schematic flowchart of a method for filtering power frequency interference in a vibration signal according to an embodiment of the present invention;

[0046] Figure 3 is a waveform diagram of a vibration signal according to an embodiment of the present invention;

[0047] Figure 4 is a waveform diagram of a first windowed signal according to an embodiment of the present invention;

[0048] Figure 5 is an amplitude spectrum of a second windowed signal according to an embodiment of the present invention;

[0049] Figure 6 is an amplitude spectrum diagram of a vibration signal with power frequency interference filtered out according to an embodiment of the present invention;

[0050] Figure 7It is a schematic structural diagram of the power frequency interference filtering system for vibration signals in the embodiments of the present invention. Detailed implementation manners

[0051] The following will clearly and completely describe the concept, specific structure and technical effects generated by the present invention in combination with the embodiments and the drawings, so as to fully understand the purpose, solution and effects of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0052] In the related art, one of the common power frequency noise interference filtering methods is the notch filter method. The existing notch filter method designs a 50Hz notch filter according to the FIR digital filtering theory, and its function expression is:

[0053] H(z) = (1 - 2(cosω)z -1 + z -2 ) / (1 - 2α(cosω)z -1 + α 2 z -2 );

[0054] In the formula, ω = 2πf / f s = 0.3066, f = 50Hz, f s is the sampling rate (1024Hz). The value of α determines the filtering effect of the notch filter. The larger its value, the deeper the notch and the narrower the width. To obtain the best filtering effect, assuming this value is taken as 0.96, the designed notch filter spectrum is as Figure 1a shown. The power frequency noise has a certain range of fluctuations. In order to effectively filter it, that is, it is necessary to make the notch filter spectrum have a certain width. At the same time, in order to reduce the damage to the useful signal, it is also necessary to make its width as narrow as possible. The result of filtering the mechanical vibration signal by the notch filter is as Figure 1b shown. It can be found that although the power frequency interference is filtered out, the useful signal is also damaged and the accuracy is poor.

[0055] To solve the above technical problems, the present invention proposes a power frequency interference filtering method, system and medium for vibration signals. By fusing the autocorrelation theory and the windowing interpolation method based on the Hanning window, first use autocorrelation processing to reduce the random noise in the vibration signal, then add a Hanning window to the vibration signal, and calculate the parameters of the accurate power frequency interference component through interpolation operation, so as to accurately filter out the power frequency interference. This algorithm has obvious advantages compared with common power frequency interference filtering methods such as notch filters and fast Fourier transforms.

[0056] Referring to Figure 2 , the present invention provides a power frequency interference filtering method for vibration signals, and the method includes the following steps:

[0057] S100. Obtain a vibration signal, perform autocorrelation operation on the vibration signal to generate an autocorrelation signal;

[0058] In this embodiment, first collect a vibration signal at a sampling frequency f s Collect N data points to generate a vibration signal x0(n), (n = 0, 1, ···, N - 1). Specifically, collect 1024 points at a sampling rate of 1024 Hz to obtain a vibration signal x0(t). The waveform of x0(t) is as Figure 3 shown.

[0059] As Figure 4 shown, perform autocorrelation on the vibration signal x0(n) to generate an autocorrelation signal x 01 (n). Through the autocorrelation operation, the random noise in the vibration signal can be effectively reduced. After the autocorrelation operation, the frequency of the power frequency signal in the signal remains unchanged, and there is a certain analytical relationship between the amplitudes, while the initial phase information is lost. Therefore, the frequency and amplitude of the power frequency signal in the vibration signal x0(n) can be calculated from x 01 (n).

[0060] Comparing Figure 4 with Figure 3 shows that the random noise is significantly reduced after the autocorrelation operation, and the subsequent analysis results are more accurate.

[0061] S200. Perform windowing processing on the autocorrelation signal to obtain a first windowed signal; perform fast Fourier transform on the first windowed signal to generate a first amplitude spectrum;

[0062] Specifically, perform fast Fourier transform on the first windowed signal x(n) to generate an amplitude spectrum. Obtain the first main lobe corresponding to the power frequency from the amplitude spectrum.

[0063] S300. Obtain the first main lobe according to the first amplitude spectrum, and calculate the amplitude and frequency of the power frequency signal according to the spectral peaks adjacent to the first main lobe;

[0064] Specifically, the amplitude and frequency of the power frequency signal in the first windowed signal x 01 (n) can be calculated based on the spectral peaks adjacent to each other on the first main lobe.

[0065] S400. Perform windowing processing on the vibration signal to obtain a second windowed signal; perform fast Fourier transform on the second windowed signal to generate a second amplitude spectrum;

[0066] S500. Obtain the second main lobe according to the second amplitude spectrum, and calculate the initial phase of the power frequency signal according to the spectral peaks adjacent to the second main lobe;

[0067] Specifically, the Hanning window interpolation formula is applied to calculate the initial phase of the power frequency signal; a Hanning window is added to the vibration signal x0(n) to generate a second windowed signal x1(n). A fast Fourier transform is performed on the second windowed signal x1(n) to generate a second amplitude spectrum, and the second main lobe corresponding to the power frequency is obtained from the second amplitude spectrum.

[0068] S600. An expression of the power frequency signal is established based on the amplitude, frequency, and initial phase of the power frequency signal, and the power frequency signal is subtracted from the vibration signal to obtain a vibration signal with power frequency interference filtered out.

[0069] Specifically, using the amplitude A0, frequency f0, and initial phase θ0 of the power frequency signal, the expression η(n) of the power frequency signal in the vibration signal can be obtained. Subtracting the power frequency signal η(n) from the vibration signal x0(n) gives a vibration signal with power frequency interference filtered out.

[0070] In the present invention, by integrating the autocorrelation theory and the windowed interpolation method, the power frequency interference in the vibration signal is filtered out, and a true interference-free vibration signal is obtained, avoiding misjudgment of the vibration condition of the steam turbine.

[0071] In some embodiments, the windowing process on the autocorrelation signal to obtain the first windowed signal includes:

[0072] The autocorrelation signal is windowed using a Hanning window function to obtain the first windowed signal.

[0073] Specifically, a Hanning window function w(n) is added to the first windowed signal x 01 (n), and a point multiplication is performed in the time domain to obtain the first windowed signal x(n), where x(n) = x 01 (n)·w(n).

[0074] In some embodiments, the calculating the amplitude and frequency of the power frequency signal according to the spectral peak values adjacent to the first main lobe includes:

[0075] Determine the first interpolation coefficient according to the amplitudes of the spectral lines on both sides of the first main lobe;

[0076] Determine the frequency of the power frequency according to the frequency of the spectral line on one side of the first main lobe, the first interpolation coefficient, the total number of data points in the vibration signal, and the sampling interval;

[0077] Determine the amplitude of the power frequency according to the amplitude of the spectral line on one side of the first main lobe and the first interpolation coefficient, and calculate the amplitude of the vibration signal according to the amplitude of the power frequency.

[0078] Specifically, let h m be the amplitude of the left spectral line on the first main lobe of the power frequency spectrum; f m be the frequency of the left spectral line on the first main lobe of the power frequency spectrum; h m+1is the amplitude of the right spectral line on the first main lobe of the power frequency spectrum; f m+1 is the frequency of the right spectral line on the first main lobe of the power frequency spectrum; phase(h m ) is the phase corresponding to h m ; T is the sampling interval.

[0079] As Figure 5 shown, the main lobe corresponding to the power frequency is obtained from the amplitude spectrum. The amplitude h Figure 5 of the left spectral line on the main lobe of the power frequency spectrum is 1.828e-05; the amplitude h m of the right spectral line on the main lobe of the power frequency spectrum is 1.162e-05; the frequency f m+1 of the left spectral line on the main lobe of the power frequency spectrum is 50.049; the frequency f m of the right spectral line on the main lobe of the power frequency spectrum is 51.050. m+1

[0080] The amplitude and frequency are represented by A and f0 respectively.

[0081] The calculation formula for the first interpolation coefficient δ is:

[0082]

[0083] where h m is the amplitude of the left spectral line on the main lobe of the power frequency spectrum, h m+1 is the amplitude of the right spectral line on the main lobe of the power frequency spectrum, and m is the data point number corresponding to the main lobe of the power frequency spectrum.

[0084] The amplitude and frequency of the power frequency signal are calculated by the following formula:

[0085]

[0086] where f m is the frequency of the left spectral line on the first main lobe of the power frequency spectrum; h m is the amplitude of the left spectral line on the first main lobe of the power frequency spectrum;

[0087] The frequency f0 obtained from the above formula is the frequency of the power frequency signal in the vibration signal x0(n).

[0088] Let the amplitude of the power frequency in the vibration signal x0(n) be A0, which can be calculated by the following formula:

[0089]

[0090] The power frequency parameters are calculated using the Hanning window interpolation formula. The amplitude A is 6.192e-05, and the frequency f0 is 50.951 Hz. From the amplitude A, A0 is further obtained as 0.011128.

[0091] In some embodiments, the windowing process of the vibration signal to obtain the second windowed signal includes:

[0092] The vibration signal is windowed using a Hanning window function, and the second windowed signal is calculated.

[0093] In some embodiments, the calculation of the initial phase of the power frequency signal based on the spectral peak adjacent to the second main lobe includes:

[0094] Determine the second interpolation coefficient according to the amplitudes of the spectral lines on both sides of the second main lobe;

[0095] Determine the initial phase of the power frequency signal according to the amplitude of the spectral line on one side of the second main lobe and the second interpolation coefficient.

[0096] Specifically, let h′ m be the amplitude of the left spectral line on the second main lobe of the power frequency spectrum; h′ m+1 be the amplitude of the right spectral line on the second main lobe of the power frequency spectrum; phase(h′ m ) be the phase corresponding to h′ m . First, calculate the second interpolation coefficient δ′, that is:

[0097]

[0098] Calculate the initial phase of the power frequency signal using the following formula:

[0099] θ0 = phase(h′ m ) - π·δ′ - 0.5π.

[0100] In some embodiments, the expression of the power frequency signal is:

[0101] η(n) = A0 cos(2πf0n / N + θ0 / π·180);

[0102] where A0 is the amplitude of the vibration signal, f0 is the frequency of the power frequency, θ0 is the initial phase of the power frequency signal, and n is the number of the data point.

[0103] Specifically, the initial phase θ0 of the power frequency signal calculated by the interpolation formula is 18.387. Thus, the expression of the power frequency signal can be obtained from the power frequency parameters. The power frequency signal is represented by η(n), that is:

[0104] η(n) = 0.011128·cos(2π·50.951·n / 1024 + 18.387·π / 180);

[0105] In the formula, n = 0, 1, ···, 1023.

[0106] Subtracting the power frequency signal η(n) from the vibration signal x0(n) gives the vibration signal with power frequency interference filtered out, which is denoted by That is:

[0107] For The amplitude spectrum generated by performing a fast Fourier transform on it is as shown in Figure 6 As can be seen from Figure 6 The power frequency interference is effectively filtered out, and the adjacent components are not affected, which has obvious advantages compared with the notch filter method.

[0108] Corresponding to the method in Figure 1, referring to Figure 7 An embodiment of the present invention provides a power frequency interference filtering system for vibration signals, including:

[0109] At least one processor;

[0110] At least one memory for storing at least one program;

[0111] When the at least one program is executed by the at least one processor, the at least one processor implements the above method.

[0112] It can be seen that the content in the above method embodiments is applicable to the system embodiments of the present invention. The functions specifically implemented by the system embodiments of the present invention are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above method embodiments.

[0113] In addition, an embodiment of the present invention also discloses a computer program product or a computer program. The computer program product or the computer program is stored in a computer-readable storage medium. The processor of the computer device can read the computer program from the computer-readable storage medium, and the processor executes the computer program so that the computer device executes the above method. Similarly, the content in the above method embodiments is applicable to the storage medium embodiments of the present invention. The functions specifically implemented by the storage medium embodiments of the present invention are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above method embodiments.

[0114] Those of ordinary skill in the art will appreciate that all or some of the methods and systems disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media typically includes computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and can include any information delivery media.

[0115] The above is a specific description of the preferred embodiments of the present disclosure, but the present disclosure is not limited to the above embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present disclosure, and these equivalent deformations or substitutions are all included in the scope defined by the claims of the present disclosure.

Claims

1. A power frequency interference filtering method for vibration signals, characterized in that, The method includes the following steps: Obtain a vibration signal, perform autocorrelation operation on the vibration signal to generate an autocorrelation signal; Perform windowing processing on the autocorrelation signal to obtain a first windowed signal; perform fast Fourier transform on the first windowed signal to generate a first amplitude spectrum; Obtain a first main lobe according to the first amplitude spectrum, and calculate the amplitude and frequency of the power frequency signal according to the spectral peaks adjacent to the first main lobe; Perform windowing processing on the vibration signal to obtain a second windowed signal; perform fast Fourier transform on the second windowed signal to generate a second amplitude spectrum; Obtain a second main lobe according to the second amplitude spectrum, and calculate the initial phase of the power frequency signal according to the spectral peaks adjacent to the second main lobe; Establish an expression of the power frequency signal according to the amplitude, frequency and initial phase of the power frequency signal, and subtract the power frequency signal from the vibration signal to obtain a vibration signal with power frequency interference filtered out.

2. The method according to claim 1, characterized in that, The performing windowing processing on the autocorrelation signal to obtain a first windowed signal includes: Perform windowing processing on the autocorrelation signal by using a Hanning window function to obtain a first windowed signal.

3. The method according to claim 1, wherein The calculating the amplitude and frequency of the power frequency signal according to the spectral peaks adjacent to the first main lobe includes: Determine a first interpolation coefficient according to the amplitudes of the spectral lines on both sides of the first main lobe; Determine the frequency of the power frequency according to the frequency of the spectral line on one side of the first main lobe, the first interpolation coefficient, the total number of data points in the vibration signal and the sampling interval; Determine the amplitude of the power frequency according to the amplitude of the spectral line on one side of the first main lobe and the first interpolation coefficient, and calculate the amplitude of the vibration signal according to the amplitude of the power frequency.

4. The method according to claim 3, characterized in that The calculation formula of the first interpolation coefficient is: where δ is the first interpolation coefficient, h m is the amplitude of the left spectral line on the main lobe of the power frequency spectrum, h m+1 is the amplitude of the right spectral line on the main lobe of the power frequency spectrum, and m is the data point number corresponding to the main lobe of the power frequency spectrum.

5. The method according to claim 4, wherein The amplitude and frequency of the power frequency signal are calculated through the following formulas: where A is the amplitude of the power frequency, f0 is the frequency of the power frequency, and f m is the frequency of the left spectral line on the first main lobe of the power frequency spectrum; h m is the amplitude of the left spectral line on the first main lobe of the power frequency spectrum; N is the total number of data points, and T is the sampling interval.

6. The method according to claim 1, wherein The performing windowing processing on the vibration signal to obtain a second windowed signal includes: Perform windowing processing on the vibration signal by using a Hanning window function to calculate and obtain a second windowed signal.

7. The method according to claim 6, characterized in that The calculating the initial phase of the power frequency signal according to the spectral peaks adjacent to the second main lobe includes: Determine a second interpolation coefficient according to the amplitudes of the spectral lines on both sides of the second main lobe; Determine the initial phase of the power frequency signal according to the amplitude of the spectral line on one side of the second main lobe and the second interpolation coefficient.

8. The method according to claim 7, characterized in that, The expression of the power frequency signal is: η(n) = A0 cos(2πf0n / N + θ0 / π·180); wherein, A0 is the amplitude of the vibration signal, f0 is the frequency of the power frequency, n is the number of the data point, and θ0 is the initial phase of the power frequency signal; The initial phase of the power frequency signal is calculated through the following formula: θ0 = phase(h′m) - π·δ′ - 0.5π; where h′ m is the amplitude of the left spectral line on the second main lobe of the power frequency spectrum; phase(h′ m ) is the phase corresponding to h′ m , and δ′ is the second interpolation coefficient.

9. A power frequency interference filtering system for vibration signals, characterized in that, The system includes: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method according to any one of claims 1 to 8.

10. A computer-readable storage medium storing a program executable by a processor, characterized in that, The program executable by the processor is used to execute the method according to any one of claims 1 to 8 when executed by the processor.

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