Real-time adaptive calculation method for prestressed steel strand tension in lightweight wind turbine hybrid tower

Abstract

The present invention discloses a real-time adaptive calculation method for the tension of prestressed steel strands in lightweight wind power hybrid towers, which is used in the field of infrastructure structure safety monitoring, including: obtaining vibration waveform data of prestressed steel strands in multiple directions; correspondingly superimposing the vibration waveform data of prestressed steel strands in multiple directions to obtain original vibration signal data; using the envelope order component algorithm to perform multi-scale decomposition processing on the original vibration signal data to obtain order component signals; screening the order component signals to obtain target order component signals, and performing fast Fourier transform to obtain the first-order vibration frequency; according to the first-order vibration frequency, calculating the real-time cable tension value of the prestressed steel strands. The present invention can timely discover the problems of looseness, corrosion or fatigue that may exist in prestressed steel strands, and take preventive maintenance measures in time, which is conducive to preventive maintenance of the structural health of the hybrid tower and optimizes the operation and maintenance management of wind power hybrid towers.

Description

Technical Field

[0001] The present invention relates to the field of infrastructure structure safety monitoring, and in particular to a real-time adaptive calculation method for prestressed steel strand tension in a lightweight wind power hybrid tower. Background Art

[0002] As a new type of structural design in the wind power industry, wind power hybrid tower combines the advantages of concrete and steel, aiming to provide higher stability and economic benefits. Its prestressed steel strands need to withstand the huge load when the wind turbine is running, and the performance status is directly related to the stability and bearing capacity of the tower structure. Therefore, the health status monitoring of the tension of the prestressed steel strands is an important measure to ensure the effective operation of the hybrid tower, and it is of great significance to establish a real-time monitoring system for the structural safety of wind power hybrid towers. By monitoring the cable tension of the prestressed steel strands, it is possible to promptly detect problems such as looseness, corrosion or fatigue of the cables, and take preventive maintenance measures in time to avoid collapse or damage of the hybrid tower structure due to cable failure.

[0003] The commonly used method for calculating the cable tension of steel strands is the vibration frequency method. However, in a large number of practical applications, due to the complex and changeable working environment of wind power towers, the vibration frequency signal of prestressed steel strands is seriously interfered by complex noise, and the frequency order is difficult to distinguish. The calculation process of the vibration frequency method often has the problem of difficulty in autonomously identifying the natural frequency of prestressed steel strands, and thus it is impossible to accurately calculate the cable tension of steel strands in real time.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0005] In order to overcome the above problems, the present invention aims to propose a real-time adaptive calculation method for the tension of prestressed steel strands in a lightweight wind turbine hybrid tower, with the aim of solving the problem that the tension of the steel strands cannot be accurately calculated in real time.

[0006] To this end, the specific technical solution adopted by the present invention is as follows:

[0007] According to one aspect of the present invention, a real-time adaptive calculation method for the tension of a prestressed steel strand in a lightweight wind power hybrid tower is provided. The real-time adaptive calculation method for the tension of a prestressed steel strand in a lightweight wind power hybrid tower comprises the following steps:

[0008] S1. Obtain vibration waveforms of the prestressed steel strands in multiple directions through monitoring equipment pre-installed on the prestressed steel strands;

[0009] S2, superimposing the vibration waveforms of the prestressed steel strand in multiple directions to obtain the original vibration signal data of the steel strand in three-dimensional space, and storing the original vibration signal data in the internal database of the sensor;

[0010] S3, using the envelope order component algorithm embedded in the sensor, multi-scale decomposition processing is performed on the original vibration signal data in the internal database of the sensor to obtain the order component signal;

[0011] S4, screening the order component signal based on the characteristic signal of the order component signal to obtain a target order component signal, and performing fast Fourier transform on the target order component signal to obtain a first-order vibration frequency;

[0012] S5. According to the first-order vibration frequency, the real-time cable tension value of the prestressed steel strand is calculated through the mathematical relationship between the cable tension and the natural frequency.

[0013] Optionally, the vibration waveforms of the prestressed steel strands in multiple directions are obtained by using monitoring equipment pre-installed on the prestressed steel strands, including:

[0014] Install the monitoring equipment in the middle of the prestressed steel strand;

[0015] The monitoring equipment is used to obtain the vibration waveforms of the prestressed steel strand in the three directions of XYZ.

[0016] Optionally, using an envelope order component algorithm embedded in the sensor, performing multi-scale decomposition processing on the original vibration signal data in the internal database of the sensor to obtain the order component signal includes the following steps:

[0017] S31, calculating the instantaneous amplitude according to the original vibration signal in the internal database of the sensor;

[0018] S32, selecting the maximum value point and the minimum value point in the instantaneous amplitude, and using a cubic spline curve to perform interpolation fitting on the maximum value point and the minimum value point of the instantaneous amplitude to obtain an extreme value fitting function;

[0019] S33, calculating an envelope using an extreme value fitting function, and removing the envelope from the original vibration signal to obtain a new component signal;

[0020] S34, using the standard deviation calculation formula to calculate the standard deviation of the new component signal, and determine whether the new component signal meets the standard deviation determination condition, if so, the new component signal is used as the envelope order signal component, and step S35 is executed, otherwise, the envelope of the new component signal is calculated, and the new component signal is updated by removing the envelope until the standard deviation of the new component signal meets the standard deviation determination condition;

[0021] S35. Subtract the envelope order signal component from the original vibration signal to obtain the residual signal component, and determine whether the residual signal component meets the preset signal condition. If so, the signal decomposition is completed and the order component signal is obtained. Otherwise, the residual signal component is used as the original vibration signal and returns to step S31.

[0022] Optionally, the instantaneous amplitude is calculated as:

[0023] ;

[0024] In the formula, A Indicates the instantaneous amplitude of the current order envelope decomposition signal; S 0 ( t ) represents the original vibration signal; PV represents the Cauchy principal value.

[0025] Optionally, the envelope curve is calculated using the extreme value fitting function as follows:

[0026] ;

[0027] In the formula, m j ( t ) represents the envelope; e max ( t ) represents the maximum fitting function; e min ( t ) represents the minimum fitting function.

[0028] Optionally, the standard deviation is calculated as:

[0029] ;

[0030] In the formula, S d represents standard deviation; h j ( t ) indicates the j The new component signal of the iteration; h j-1 ( t ) indicates the j - New component signal for 1 iteration; n Indicates the total time, t Indicates time.

[0031] Optionally, the standard deviation judgment condition is:

[0032] The standard deviation of the new component signal is less than 0.2, and the number of zero points and extreme value points of the new component signal is the same or differs by at most one.

[0033] Optionally, the preset signal condition is:

[0034] The residual signal component satisfies the monotonic condition or the number of extreme points of the residual signal component does not exceed 2.

[0035] Optionally, according to the first-order vibration frequency, by using the mathematical relationship between the cable force and the natural frequency, calculating the real-time cable force value of the prestressed steel strand comprises the following steps:

[0036] S51. Based on the theory of string vibration, determine the mathematical relationship between the tension of the prestressed steel strand and the natural frequency of the prestressed steel strand;

[0037] S52, according to the mathematical relationship between the tension of the prestressed steel strand and the natural frequency of the prestressed steel strand, and by using an analytical method to determine the mathematical relationship between the first-order vibration frequency and the cable force value;

[0038] S53. Utilize the mathematical relationship between the first-order vibration frequency and the cable force value, and calculate the real-time cable force value of the prestressed steel strand based on the first-order vibration frequency.

[0039] Optionally, the mathematical relationship between the first-order vibration frequency and the cable force value is expressed as:

[0040] ;

[0041] In the formula, T It means the force of the rope; m Indicates the linear density of the steel strand; g is the acceleration due to gravity; L is the cable length of the steel strand; f 1 is the first-order vibration frequency.

[0042] Compared with the prior art, the present application has the following beneficial effects: the present invention effectively solves the problems in the current wind power hybrid tower monitoring field, such as inaccurate screening of main frequency signals, inability to determine fundamental frequency, and excessive errors in cable force calculation; by monitoring cable force, it is possible to promptly discover problems such as looseness, corrosion or fatigue in prestressed steel strands, and take preventive maintenance measures in a timely manner to avoid collapse or damage of the tower structure caused by failure of the prestressed cable, which is beneficial to preventive maintenance of the structural health of the hybrid tower, optimize the operation and maintenance management of the wind power hybrid tower, and improve the economic efficiency of wind power. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 is a flow chart of a method for real-time adaptive calculation of tension in prestressed steel strands of a lightweight wind power hybrid tower according to an embodiment of the present invention;

[0045] Figure 2 It is a schematic diagram of calculating the first-order vibration natural frequency of prestressed steel strands in a real-time adaptive calculation method for tension of prestressed steel strands in a lightweight wind power hybrid tower according to an embodiment of the present invention;

[0046] Figure 3 It is a time domain diagram of the original vibration data in the real-time adaptive calculation method for tension of prestressed steel strands in a lightweight wind power hybrid tower according to an embodiment of the present invention;

[0047] Figure 4 It is a schematic diagram of the FFT change of the original vibration data in the real-time adaptive calculation method of the tension of the prestressed steel strand of the lightweight wind power hybrid tower according to an embodiment of the present invention;

[0048] Figure 5 This is a schematic diagram of the first signal decomposition in the real-time adaptive calculation method for tension of prestressed steel strands in a lightweight wind power hybrid tower according to an embodiment of the present invention;

[0049] Figure 6 It is a schematic diagram of signal decomposition completion in a real-time adaptive calculation method for tension of prestressed steel strands in a lightweight wind power hybrid tower according to an embodiment of the present invention;

[0050] Figure 7 It is a FFT variation diagram of the target order component in the real-time adaptive calculation method for tension of prestressed steel strands in a lightweight wind power hybrid tower according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0052] According to an embodiment of the present invention, a real-time adaptive calculation method for tension of prestressed steel strands in a lightweight wind turbine hybrid tower is provided.

[0053] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 1-Figure 7 As shown, according to the real-time adaptive calculation method for the tension of prestressed steel strands in a lightweight wind power hybrid tower according to an embodiment of the present invention, the real-time adaptive calculation method for the tension of prestressed steel strands in a lightweight wind power hybrid tower comprises the following steps:

[0054] S1. Obtain the vibration waveforms of the prestressed steel strands in multiple directions through monitoring equipment pre-installed on the prestressed steel strands.

[0055] Preferably, obtaining vibration waveforms of the prestressed steel strand in multiple directions by monitoring equipment pre-installed on the prestressed steel strand includes:

[0056] Install the monitoring equipment in the middle of the prestressed steel strand;

[0057] The monitoring equipment is used to obtain the vibration waveforms of the prestressed steel strand in the three directions of XYZ.

[0058] It should be explained that for the prestressed steel strands that need to be measured, the BOWEI-V200 lightweight monitoring terminal should be fixed and preferably installed in the middle section of the cable or in the area where the force is concentrated to ensure the accuracy of signal acquisition. Ensure that the sensor tightly holds the entire steel strand and does not interfere with other structures or equipment, enhance working stability, and avoid external interference.

[0059] S2. Superimpose the vibration waveforms of the prestressed steel strands in multiple directions to obtain the original vibration signal data of the steel strands in three-dimensional space, and store the original vibration signal data in the internal database of the sensor.

[0060] It should be explained that the vibration waveforms in the three directions of XYZ are collected in real time, the collected data are added accordingly, and the three-dimensional original vibration data of the steel strand is obtained by superposition and merging and stored in the internal database of the sensor. Figure 3 As shown (in the figure, Time represents time and Acceleration represents acceleration), the three-dimensional original vibration data of the steel strand is obtained.

[0061] Due to the complex on-site measurement environment, there are many interference factors. The location and fixing method of the sensor, ground environment vibration and other factors will interfere with the vibration signal. If the interference is not filtered out and the invalid signal is not separated, the traditional method is used to directly perform Fourier transform, such as Figure 4 As shown in the figure (Frequency represents frequency, Magnitude represents signal strength), the vibration data is seriously interfered by background noise, the frequency spectrum signal is messy, it is difficult to obtain stable and accurate vibration frequency orders, and it is difficult to extract the first-order vibration frequency of the steel strand.

[0062] S3. Using the envelope order component algorithm embedded in the sensor, the original vibration signal data in the internal database of the sensor is subjected to multi-scale decomposition processing to obtain the order component signal.

[0063] Preferably, using the envelope order component algorithm embedded in the sensor, the original vibration signal data in the internal database of the sensor is subjected to multi-scale decomposition processing to obtain the order component signal, which includes the following steps:

[0064] S31, calculating the instantaneous amplitude according to the original vibration signal in the internal database of the sensor;

[0065] S32, selecting the maximum value point and the minimum value point in the instantaneous amplitude, and using a cubic spline curve to perform interpolation fitting on the maximum value point and the minimum value point of the instantaneous amplitude to obtain an extreme value fitting function;

[0066] S33, calculating an envelope using an extreme value fitting function, and removing the envelope from the original vibration signal to obtain a new component signal;

[0067] S34, using the standard deviation calculation formula to calculate the standard deviation of the new component signal, and determine whether the new component signal meets the standard deviation determination condition, if so, the new component signal is used as the envelope order signal component, and step S35 is executed, otherwise, the envelope of the new component signal is calculated, and the new component signal is updated by removing the envelope until the standard deviation of the new component signal meets the standard deviation determination condition;

[0068] S35. Subtract the envelope order signal component from the original vibration signal to obtain the residual signal component, and determine whether the residual signal component meets the preset signal condition. If so, the signal decomposition is completed and the order component signal is obtained. Otherwise, the residual signal component is used as the original vibration signal and returns to step S31.

[0069] Preferably, the calculation formula of the instantaneous amplitude is:

[0070] ;

[0071] In the formula, A Indicates the instantaneous amplitude of the current order envelope decomposition signal; S 0 ( t ) represents the original vibration signal; PV represents the Cauchy principal value.

[0072] Preferably, the calculation formula for calculating the envelope using the extreme value fitting function is:

[0073] ;

[0074] In the formula, m j ( t ) represents the envelope; e max ( t ) represents the maximum fitting function; e min ( t ) represents the minimum fitting function.

[0075] Preferably, the calculation formula of the standard deviation is:

[0076] ;

[0077] In the formula, S d represents standard deviation; h j ( t ) indicates the j The new component signal of the iteration; h j-1 ( t ) indicates the j - New component signal for 1 iteration; n Indicates the total time, t Indicates time.

[0078] Preferably, the standard deviation judgment condition is:

[0079] The standard deviation of the new component signal is less than 0.2, and the number of zero points and extreme value points of the new component signal is the same or differs by at most one.

[0080] Preferably, the preset signal condition is:

[0081] The residual signal component satisfies the monotonic condition or the number of extreme points of the residual signal component does not exceed 2.

[0082] It needs to be explained that Figure 2 As shown in the figure (the residual component represents the remaining signal component, and FFT represents fast Fourier transform), the original vibration data stored in the sensor database is analyzed and processed using a custom algorithm embedded in the sensor to decompose the vibration signal at multiple scales.

[0083] First, create two blank signal components S i ( t )and h 0 ( t ),initialization i =1, S 0 ( t ) is equal to the original vibration signal, S i ( t ) is the current order envelope decomposition signal, h 0 ( t )= S i-1 ( t ), calculate the instantaneous amplitude according to the instantaneous amplitude formula A , instantaneous amplitude A The calculation formula is:

[0084] ;

[0085] In the formula, A Indicates the instantaneous amplitude of the current order envelope decomposition signal; S 0 ( t ) represents the original vibration signal; PV represents the Cauchy principal value.

[0086] Calculate its instantaneous amplitude A , and its value points a max and minimum point a min Cubic spline curve pair a max and a min Perform interpolation fitting to obtain the extreme value fitting function e max ( t )and e min ( t ).pass e max ( t )and e min ( t ) Calculate the instantaneous envelope m j ( t ),use h 0 ( t ) minus the envelope m j ( t )(from h 0 ( t ) signal is removed m j ( t ) signal) to obtain a new component signal h j ( t ), j =1.

[0087] Calculate the envelope using the extreme value fitting function m j ( t ) is calculated as:

[0088] ;

[0089] In the formula, m j ( t ) represents the envelope; e max (t ) represents the maximum fitting function; e min ( t ) represents the minimum fitting function.

[0090] calculate h j ( t ) The standard deviation of the component signal S d , standard deviation S d The calculation formula is:

[0091] ;

[0092] In the formula, S d represents standard deviation; h j ( t ) indicates the j The new component signal of the iteration; h j-1 ( t ) indicates the j - New component signal for 1 iteration; n Indicates the total time, t Indicates time.

[0093] if S d If the value of is less than 0.2, and the number of zero points and extreme points is the same or differs by at most 1, then h j ( t ) is extracted as an order component signal; otherwise, let j = j +1, calculate the new component by formula h j ( t ) m j ( t ), and repeat the above steps until it can be recorded as an envelope order component. Figure 5 As shown in the figure (Time represents time, Acceleration represents acceleration), the vibration signal is successfully extracted after one decomposition is completed.

[0094] By continuously removing the order components that meet the requirements from the original signal, if the remaining information components S i ( t ) satisfies monotonicity or has no more than 2 extreme points, the decomposition is terminated and the original vibration signal is successfully decomposed into several signals. Figure 6As shown, 10 order components are decomposed from the original vibration signal. Otherwise, let i = i +1, S i ( t ) as the new original vibration signal and repeat the above steps for decomposition.

[0095] S4. Screening the order component signal based on the characteristic signal of the order component signal to obtain a target order component signal, and performing fast Fourier transform on the target order component signal to obtain a first-order vibration frequency.

[0096] It should be explained that after the decomposition is completed, screening is performed to match specific frequencies, and characteristic signals with clear frequencies are selected from the decomposed order component spectra as the target natural frequencies to further improve accuracy.

[0097] like Figure 7 As shown in the figure (Frequency represents frequency, Magnitude represents signal strength), Figure 6 By performing fast Fourier transform on the third envelope order component in the envelope order component, the first-order vibration frequency can be clearly extracted from the changed vibration spectrum.

[0098] S5. According to the first-order vibration frequency, the real-time cable tension value of the prestressed steel strand is calculated through the mathematical relationship between the cable tension and the natural frequency.

[0099] Preferably, according to the first-order vibration frequency, by using the mathematical relationship between the cable force and the natural frequency, calculating the real-time cable force value of the prestressed steel strand comprises the following steps:

[0100] S51. Based on the theory of string vibration, determine the mathematical relationship between the tension of the prestressed steel strand and the natural frequency of the prestressed steel strand;

[0101] S52, according to the mathematical relationship between the tension of the prestressed steel strand and the natural frequency of the prestressed steel strand, and by using an analytical method to determine the mathematical relationship between the first-order vibration frequency and the cable force value;

[0102] S53. Utilize the mathematical relationship between the first-order vibration frequency and the cable force value, and calculate the real-time cable force value of the prestressed steel strand based on the first-order vibration frequency.

[0103] Preferably, the mathematical relationship between the first-order vibration frequency and the cable force value is expressed as:

[0104] ;

[0105] In the formula, T It means the force of the rope; m Indicates the linear density of the steel strand; gis the acceleration due to gravity; L The length of the steel strand; f 1 is the first-order vibration frequency.

[0106] It should be explained that, using the string vibration theory, we can get the mathematical relationship between the tension of the steel strand cable and its natural frequency.

[0107] ;

[0108] In the formula, represents the vibration frequency order, g represents the acceleration due to gravity, m Indicates the linear density of the steel strand, EI It represents the bending stiffness of the steel strand. y Indicates the length direction of the steel strand. T Indicates the force, t Indicates time.

[0109] Without considering the sag and bending stiffness of the steel strand itself, and based on the mathematical relationship between the tension of the steel strand cable and its natural frequency, removing the influence of the prestressed steel strand itself, the analytical method can be used to obtain:

[0110] ;

[0111] In the formula, T It means the force of the rope; m Indicates the linear density of the steel strand; g is the acceleration due to gravity; L is the cable length of the steel strand; f 1 is the first-order vibration frequency, obtained by the algorithm.

[0112] To summarize, with the aid of the above-mentioned technical scheme of the present invention, the present invention is based on the BOWEI-V200 integrated lightweight monitoring device (highly integrated three-way vibration sensor, high-speed data acquisition instrument, edge computing module), real-time acquisition of vibration signals in three directions of XYZ, and adaptively calculates the cable tension in real time based on the embedded algorithm, and has good robustness and stability; the present invention is based on the envelope order component algorithm to decompose the original data, eliminate invalid background noise interference, thereby extracting the target natural frequency and frequency order, and can accurately determine the first-order vibration frequency, and then calculate the real-time cable tension value according to the formula, which can accurately monitor the cable tension change fluctuation of the prestressed steel strand, and provide guidance and suggestions for the safe operation and maintenance of wind power hybrid towers and risk investigation; the algorithm in the present invention can autonomously calculate the cable tension in real time through integrated hardware and adaptive algorithms, without the need for manual and background analysis, which greatly reduces the difficulty and complexity of project implementation.

[0113] Although the present invention has been disclosed as above with preferred embodiments, the embodiments are merely examples for the convenience of description and are not intended to limit the present invention. Those skilled in the art may make several changes and modifications without departing from the spirit and scope of the present invention. The scope of protection claimed by the present invention shall be based on the claims.

Claims

1. A real-time adaptive calculation method for tension of prestressed steel strands in lightweight wind turbine hybrid towers, characterized in that: The following steps are involved: S1. Obtain vibration waveforms of the prestressed steel strands in multiple directions through monitoring equipment pre-installed on the prestressed steel strands; S2, superimposing the vibration waveforms of the prestressed steel strand in multiple directions to obtain the original vibration signal data of the steel strand in three-dimensional space, and storing the original vibration signal data in the internal database of the sensor; S3, using the envelope order component algorithm embedded in the sensor, multi-scale decomposition processing is performed on the original vibration signal data in the internal database of the sensor to obtain the order component signal; S4, screening the order component signal based on the characteristic signal of the order component signal to obtain a target order component signal, and performing fast Fourier transform on the target order component signal to obtain a first-order vibration frequency; S5. Calculate the real-time cable force value of the prestressed steel strand according to the first-order vibration frequency and the mathematical relationship between the cable force and the natural vibration frequency; The S3 comprises the following steps: S31, calculating the instantaneous amplitude according to the original vibration signal in the internal database of the sensor; S32, selecting the maximum value point and the minimum value point in the instantaneous amplitude, and using a cubic spline curve to perform interpolation fitting on the maximum value point and the minimum value point of the instantaneous amplitude to obtain an extreme value fitting function; S33, calculating an envelope using an extreme value fitting function, and removing the envelope from the original vibration signal to obtain a new component signal; S34, using the standard deviation calculation formula to calculate the standard deviation of the new component signal, and determine whether the new component signal meets the standard deviation determination condition, if so, the new component signal is used as the envelope order signal component, and step S35 is executed, otherwise, the envelope of the new component signal is calculated, and the new component signal is updated by removing the envelope until the standard deviation of the new component signal meets the standard deviation determination condition; S35. Subtract the envelope order signal component from the original vibration signal to obtain the residual signal component, and determine whether the residual signal component meets the preset signal condition. If so, the signal decomposition is completed and the order component signal is obtained. Otherwise, the residual signal component is used as the original vibration signal and returns to step S31.

2. The method for real-time adaptive calculation of tension of prestressed steel strands in lightweight wind power hybrid tower according to claim 1 is characterized in that: The method of obtaining vibration waveforms of the prestressed steel strand in multiple directions by using monitoring equipment pre-installed on the prestressed steel strand includes: Install the monitoring equipment in the middle of the prestressed steel strand; The monitoring equipment is used to obtain the vibration waveforms of the prestressed steel strand in the three directions of XYZ.

3. The method for real-time adaptive calculation of tension of prestressed steel strands in lightweight wind power hybrid tower according to claim 1 is characterized in that: The calculation formula of the instantaneous amplitude is: ； In the formula, A Indicates the instantaneous amplitude of the current order envelope decomposition signal; S 0( t ) represents the original vibration signal; PV represents the Cauchy principal value.

4. The method for real-time adaptive calculation of tension of prestressed steel strands in lightweight wind power hybrid tower according to claim 1 is characterized in that: The calculation formula for calculating the envelope using the extreme value fitting function is: ； In the formula, m j ( t ) represents the envelope; e max ( t ) represents the maximum fitting function; e min ( t ) represents the minimum fitting function.

5. The method for real-time adaptive calculation of tension of prestressed steel strands in lightweight wind power hybrid tower according to claim 1 is characterized in that: The standard deviation is calculated as: ； In the formula, S d represents standard deviation; h j ( t ) indicates the j The new component signal of the iteration; h j-1 ( t ) indicates the j - New component signal for 1 iteration; n Indicates the total time, t Indicates time.

6. The method for real-time adaptive calculation of tension of prestressed steel strands in lightweight wind power hybrid tower according to claim 1 is characterized in that: The standard deviation judgment condition is: The standard deviation of the new component signal is less than 0.2, and the number of zero points and extreme value points of the new component signal is the same or differs by at most one.

7. The method for real-time adaptive calculation of tension of prestressed steel strands in lightweight wind power hybrid tower according to claim 1 is characterized in that: The preset signal condition is: The residual signal component satisfies the monotonic condition or the number of extreme points of the residual signal component does not exceed 2.

8. The method for real-time adaptive calculation of tension of prestressed steel strands in lightweight wind power hybrid tower according to claim 1 is characterized in that: The method of calculating the real-time cable force value of the prestressed steel strand according to the first-order vibration frequency through the mathematical relationship between the cable force and the natural vibration frequency comprises the following steps: S51. Based on the theory of string vibration, determine the mathematical relationship between the tension of the prestressed steel strand and the natural frequency of the prestressed steel strand; S52, according to the mathematical relationship between the tension of the prestressed steel strand and the natural frequency of the prestressed steel strand, and by using an analytical method to determine the mathematical relationship between the first-order vibration frequency and the cable force value; S53. Utilize the mathematical relationship between the first-order vibration frequency and the cable force value, and calculate the real-time cable force value of the prestressed steel strand based on the first-order vibration frequency.

9. The method for real-time adaptive calculation of tension of prestressed steel strands in lightweight wind power hybrid tower according to claim 8 is characterized in that: The mathematical relationship between the first-order vibration frequency and the cable force value is expressed as follows: ； In the formula, T It means the force of the rope; m Indicates the linear density of the steel strand; g is the acceleration due to gravity; L is the cable length of the steel strand; f 1 is the first-order vibration frequency.

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