CN113326592A - Fan blade fault analysis method and system based on modal decomposition algorithm - Google Patents

Fan blade fault analysis method and system based on modal decomposition algorithm Download PDF

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CN113326592A
CN113326592A CN202110889034.0A CN202110889034A CN113326592A CN 113326592 A CN113326592 A CN 113326592A CN 202110889034 A CN202110889034 A CN 202110889034A CN 113326592 A CN113326592 A CN 113326592A
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CN113326592B (en
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尹旭晔
水沛
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ZHEJIANG CHTRICSAFEWAY NEW ENERGY TECHNOLOGY CO LTD
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Abstract

The invention discloses a fan blade fault analysis method based on a modal decomposition algorithm, which comprises the following steps: equally dividing the solid fan blade into N +1 blade sections to obtain a spatial coordinate matrix of M contour points of each blade section; constructing a fan blade digital twin model, and calculating the space coordinates of M contour points of each simulated blade section; calculating and simulating by finite element analysis software to obtain a simulated space coordinate matrix of M contour points of each blade section of the fan blade in a working state; the method comprises the steps of obtaining a real-time space coordinate matrix of M contour points of each blade section of an entity fan blade in a working state through optical fiber measurement, carrying out difference on the real-time space coordinate matrix and a simulation space coordinate matrix to obtain a residual error matrix, and judging the entity fan blade to be in a fault state if the residual error matrix is larger than a threshold value. The invention carries out complete and comprehensive fault detection on the working state of the fan blade.

Description

Fan blade fault analysis method and system based on modal decomposition algorithm
Technical Field
The invention relates to the technical field of blade fault analysis, in particular to a fan blade fault analysis method and system based on a modal decomposition algorithm.
Background
In recent years, the wind power industry in China develops rapidly, and the capacity of a wind generating set increases year by year. The large-scale fan often operates in a relatively severe external environment, the operation condition is severe, and the failure rate of the wind turbine generator is high due to the severe environment. The failure causes are various, wherein the proportion of the failure with cracks of the fan blade in the failure of the wind turbine generator is quite high, and the failure seriously affects the economic benefit of wind power enterprises. When the fan blade has serious faults, the blade is difficult to maintain and the maintenance cost is extremely high, so that fault detection and fault prediction are carried out on the large fan blade, and the method has important significance for reducing the operation and maintenance cost and improving the economic benefit of enterprises.
When the blade of the wind driven generator has cracks, the mechanism for effectively identifying the crack characteristics is very complicated because different cracks are in different states. At present, the traditional fan blade inspection scheme mainly has: static detection, fatigue detection, model analysis, and the like. Various types of sensors are arranged and installed on the fan blade, and crack damage detection is carried out by collecting signals of the sensors, but the scheme only monitors local characteristic points of the fan blade and cannot cover the whole fan blade, so that the accuracy of fault detection is not high.
The technical scheme of the existing fan blade detection is mainly based on vibration monitoring, and the vibration monitoring scheme has the problems that the vibration sensors can only be installed in a plurality of places, the obtained vibration data are limited, the damage place of the blade can be far away from the installed sensors, and the influence on the sensors is small. The invention discloses a method for extracting optical fiber load strain characteristics and monitoring cracks of a fan blade, which is disclosed by the patent application with the publication number of CN 108592812A. The patent application with the publication number of CN113049410A is based on a strain nonlinear weighted composite material laminate optical fiber impact position identification method, the invention identifies the position of impact occurrence on a material plate through a pipeline, for fan blade monitoring, the influence caused by long-term operation of the pipeline is needed, and the requirement on positioning of sudden load is not large. The invention discloses a crack detection method of a fan blade in patent application with publication number CN112945531A, which is based on the analysis of equipment vibration frequency spectrum and determines the defects of the fan blade by capturing the characteristics of crack vibration signals.
Disclosure of Invention
In view of the above, the invention provides a fan blade fault analysis method and system based on a modal decomposition algorithm, which are based on a computer-aided technology to perform complete and comprehensive fault detection on the working state of a fan blade.
In order to achieve the above object, the present invention provides a fan blade fault analysis method based on a modal decomposition algorithm, the method comprising the steps of:
s1, equally dividing the solid fan blade into N +1 blade sections along the radial direction of an impeller of the solid fan blade, and measuring the section of each blade section, wherein the section measuring step comprises the following steps: equally dividing each blade section into M contour points along the circumferential direction of the section, and calculating to obtain the spatial coordinates of the M contour points to obtain a spatial coordinate matrix of the M contour points of each blade section of the entity fan blade in a non-operating state;
s2, constructing a fan blade digital twin model of a geometric structure corresponding to the entity fan blade, intercepting a plurality of simulation blade sections between two adjacent blade sections in the fan blade digital twin model, and calculating the spatial coordinates of M contour points of each simulation blade section according to the spatial coordinates of the M contour points of the two adjacent blade sections so as to obtain a spatial coordinate matrix of any position of the entity fan blade in a non-working state;
s3, inputting the space coordinate matrix of any position of the entity fan blade in the non-operating state and the material information of the fan blade into finite element analysis software, and calculating and simulating to obtain the mode coefficient matrix of the first S modes of the fan blade in the operating state under the respective states of shimmy, flap and torsion;
s4, calculating to obtain a simulation space coordinate matrix of M contour points of each blade section of the fan blade in a working state according to the mode coefficient matrixes of the first S modes of the fan blade in the respective states of shimmy, waving and torsion;
s5, arranging optical fibers on the solid fan blade, and obtaining a real-time space coordinate matrix of M contour points of each blade section of the solid fan blade in a working state through optical fiber measurement;
and S6, carrying out difference on the real-time space coordinate matrix and the simulation space coordinate matrix to obtain a residual error matrix, and if the residual error matrix is greater than a threshold value, judging that the entity fan blade is in a fault state.
Preferably, the step S1 includes:
the method comprises the steps that a first preset position is arranged on a solid fan blade, a first preset distance is reserved between the first preset position and the top end of the blade tip of the solid fan blade, the fan blade from the cylindrical blade root of the solid fan blade to the first preset position along the radial direction of an impeller is divided into N equal parts, and N +1 equal-divided blade sections are formed.
Preferably, the step S1 further includes:
equally dividing the blade section into M contour points along the section circumferential direction from the trailing edge on each blade section;
calculating the impeller radial position ln of each blade section through the formula (1):
Figure DEST_PATH_IMAGE002A
（1）；
wherein lnThe radial position of an impeller of the section of the nth blade is shown, L is the distance from the center of the blade root of the fan blade to a first preset position, and N is 0-N;
calculating the corresponding azimuth angle phi of each contour point by formula (2)m；
Figure DEST_PATH_IMAGE004A
（2）；
Wherein M is the mth contour point on the blade section, and the value is between 0 and M, phimIs the azimuth angle, phi, of the mth profile point on the blade section relative to the center of the blade sectionmPerforming M equal division between 0 and 360 degrees;
measuring the profile coefficient R of each profile point of each blade sectionn(φm) The profile coefficient is used for representing the distance from a profile point to the center of the corresponding blade section;
the radial position l of the impeller of the blade sectionnAzimuth angle phi of each contour pointmAnd the contour coefficients of the M contour points form the space coordinates of the M contour points of the blade section, and the space coordinate set of the M contour points of each blade section is the space coordinate matrix C of the M contour points of each blade section of the entity fan blade in the non-operating staten：
Figure DEST_PATH_IMAGE006A
（3）；
Wherein, CnIs a geometric matrix of contour points of the nth blade section, lnRadial position of the impeller at the section of the nth blademAzimuth angle, R, of the m-th contour pointn(φm) Is the profile factor of the mth profile point of the nth blade section.
Preferably, the step S1 further includes:
all the profile coefficients of the N +1 blade sections of the solid fan blade form a profile coefficient matrix R of the solid fan blade in a non-working state:
Figure DEST_PATH_IMAGE008A
（4）；
wherein R isn(φm) Is the profile factor of the mth profile point of the nth blade section.
Preferably, the step S2 includes:
any simulated blade section R is cut between the nth blade section and the (n +1) th blade section, the simulated blade section R is equally divided into M contour points along the circumferential direction of the section, and the contour coefficient R of the mth contour point of the nth blade section is determined according to the contour coefficient R of the mth contour pointn(φm) And the profile coefficient R of the (n +1) th blade sectionn+1(φm) And the radial position l of the impeller according to the obtained simulated blade section rrCalculating the profile coefficient R of the mth profile point of the simulated blade section R by the formula (5)r(φm) And acquiring profile coefficients of all profile points of the simulated blade section r:
Figure DEST_PATH_IMAGE010A
（5）；
wherein lnRadial position of the impeller at the section of the nth blade,/n+1The impeller radial position of the (n +1) th blade section;
by analogy, calculating the contour coefficients of all contour points of any simulated blade section r of the fan blade in the fan blade digital twin model;
vane radial position l of blade section to be simulatedrM azimuth angles phi of contour pointsmAnd the contour coefficient R of M contour pointsr(φm) The spatial coordinates C (l) of the M contour points constituting the simulated blade section rr)：
Figure DEST_PATH_IMAGE012A
（6）；
And obtaining a space coordinate matrix of any position of the entity fan blade in the non-operating state.
Preferably, the step S3 includes:
the fan blade has multiple modes under the shimmy state, and multiple modes correspond a plurality of different natural frequencies, and according to natural frequency from low to high in proper order to the mode sequencing, select first S modes, the mode coefficient matrix of first S modes is:
Figure DEST_PATH_IMAGE014A
（7）；
wherein f isi,m,nThe modal coefficient of the mth profile point of the nth fan blade section in the ith mode of the fan blade in the shimmy state is represented as fi,0,0The reference coefficient in the shimmy state is 1, i is 1-S, N is 0-N, and M is 0-M;
the fan blade has multiple modality at the state of waving, and multiple modality corresponds a plurality of different natural frequencies, sorts the modality according to natural frequency from low to high in proper order, selects first S modalities, the mode coefficient matrix of first S modalities is:
Figure DEST_PATH_IMAGE016A
（8）；
wherein e isj,m,nThe reference coefficient of the mth contour point of the nth fan blade section in the jth mode in the flapping state of the fan blade is represented, j takes the value of 1-S, ej,0,0The reference coefficient in the waving state is 1, N is 0-N, and M is 0-M;
the fan blade has multiple modes in the bending state, the multiple modes correspond to multiple different natural frequencies, the modes are sequenced from low to high according to the natural frequencies, the first S modes are selected, and the mode coefficient matrix of the first S modes is as follows:
Figure DEST_PATH_IMAGE018A
（9）；
wherein, tk,m,nThe modal coefficient of the mth profile point of the nth fan blade section under the kth modal in the bending state of the fan blade is represented, wherein k is 1-S, and tk,0,0The reference coefficient in the bending state is 1, N is 0-N, and M is 0-M.
Preferably, the step S3 includes:
the simulation contour coefficient matrix of the M contour points of each blade section is a linear combination equation of the modal coefficient matrix of the first S modes of the fan blade in the respective states of shimmy, flapping and torsion, and the linear combination equation is as follows:
Figure DEST_PATH_IMAGE020
（10）；
wherein, ai, bj,ckIs a linear equation coefficient;
the step S4 includes:
all the profile coefficients of the N +1 blade sections of the solid fan blade form a real-time profile coefficient matrix of the solid fan blade in a working state:
Figure DEST_PATH_IMAGE022
（11）。
preferably, the step S5 includes:
the residual matrix res is:
Figure DEST_PATH_IMAGE024
（12）。
preferably, the step S5 includes:
calculating the displacement offset D of each contour point in the N +1 blade sections according to the real-time contour coefficient matrix of the entity fan blade and the contour coefficient of the contour point of the blade section of the fan blade in the non-operating statem,n：
Figure DEST_PATH_IMAGE026
（13）；
Will calculate all Dm,nSequentially arranging from large to small, and sequentially selecting 3S D from the maximum valuem,n；
3S Dm,nSubstituting the corresponding real-time contour coefficient into the equation (10), and solving to obtain a linear equation coefficient a1,a2,…,aS,b1,b2,…,bS,c1,c2,…,cS；
Substituting the solved linear equation coefficient into an equation (12) to obtain a residual error matrix res;
after the absolute values of all the elements in the residual error matrix res are obtained, if the absolute values are larger than a threshold value, the entity fan blade is judged to be in a fault state, otherwise, the entity fan blade is judged to be in a normal state.
In order to achieve the above object, the present invention provides a fan blade fault analysis system based on a modal decomposition algorithm, the system comprising:
the cross section measuring module is used for equally dividing the solid fan blade into N +1 blade cross sections along the radial direction of an impeller of the solid fan blade, and measuring the cross section of each blade cross section, wherein the cross section measuring step comprises the following steps: equally dividing each blade section into M contour points along the circumferential direction of the section, and calculating to obtain the spatial coordinates of the M contour points to obtain a spatial coordinate matrix of the M contour points of each blade section of the entity fan blade in a non-operating state;
the digital twin model module is used for constructing a fan blade digital twin model of a geometric structure corresponding to the entity fan blade, a plurality of simulated blade sections are intercepted between two adjacent blade sections in the fan blade digital twin model, and the spatial coordinates of M contour points of each simulated blade section are calculated according to the spatial coordinates of the M contour points of the two adjacent blade sections, so that a spatial coordinate matrix of any position of the entity fan blade in a non-working state is obtained;
the finite element analysis module is used for inputting the space coordinate matrix of any position of the entity fan blade in the non-working state and the material information of the fan blade into finite element analysis software, and calculating and simulating to obtain modal coefficient matrixes of the first S modes of the fan blade in the working state under the respective states of shimmy, flap and torsion;
the calculation module is used for calculating and obtaining a simulation space coordinate matrix of M contour points of each blade section of the fan blade in a working state according to the mode coefficient matrixes of the first S modes of the fan blade in the respective states of shimmy, flapping and torsion;
the optical fiber measurement module is used for arranging optical fibers on the solid fan blade and obtaining a real-time space coordinate matrix of M contour points of each blade section of the solid fan blade in a working state through optical fiber measurement;
and the judging module is used for carrying out difference on the real-time space coordinate matrix and the simulation space coordinate matrix to obtain a residual error matrix, and if the residual error matrix is greater than a threshold value, judging that the entity fan blade is in a fault state.
Compared with the prior art, the fan blade fault analysis method and system based on the modal decomposition algorithm have the following beneficial effects: by using distributed optical fiber measurement, the real-time form change of the whole fan blade can be obtained completely, so that the working state of the fan blade is evaluated completely and comprehensively; all possible normal operation forms of the fan blade are obtained by using a computer-aided method, and are compared and verified with the complete form monitoring of the fan blade, so that the blade fault is accurately captured.
Drawings
FIG. 1 is a schematic flow diagram of a method for analyzing a failure of a wind turbine blade based on a modal decomposition algorithm according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view of a blade according to an embodiment of the invention.
FIG. 3 is a schematic view of a fan blade fiber arrangement according to an embodiment of the present invention.
FIG. 4 is a system diagram of a fan blade fault analysis system based on a modal decomposition algorithm, according to one embodiment of the invention.
Detailed Description
The present invention will be described in detail with reference to the specific embodiments shown in the drawings, which are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to the specific embodiments are included in the scope of the present invention.
In an embodiment of the present invention shown in fig. 1, the present invention provides a method for analyzing a failure of a fan blade based on a modal decomposition algorithm, the method comprising the steps of:
s1, equally dividing the solid fan blade into N +1 blade sections along the radial direction of an impeller of the solid fan blade, and measuring the section of each blade section, wherein the section measuring step comprises the following steps: equally dividing each blade section into M contour points along the circumferential direction of the section, and calculating to obtain the spatial coordinates of the M contour points to obtain a spatial coordinate matrix of the M contour points of each blade section of the entity fan blade in a non-operating state;
s2, constructing a fan blade digital twin model of a geometric structure corresponding to the entity fan blade, intercepting a plurality of simulation blade sections between two adjacent blade sections in the fan blade digital twin model, and calculating the spatial coordinates of M contour points of each simulation blade section according to the spatial coordinates of the M contour points of the two adjacent blade sections so as to obtain a spatial coordinate matrix of any position of the entity fan blade in a non-working state;
s3, inputting the space coordinate matrix of any position of the entity fan blade in the non-operating state and the material information of the fan blade into finite element analysis software, and calculating and simulating to obtain the mode coefficient matrix of the first S modes of the fan blade in the operating state under the respective states of shimmy, flap and torsion;
s4, calculating to obtain a simulation space coordinate matrix of M contour points of each blade section of the fan blade in a working state according to the mode coefficient matrixes of the first S modes of the fan blade in the respective states of shimmy, waving and torsion;
s5, arranging optical fibers on the solid fan blade, and obtaining a real-time space coordinate matrix of M contour points of each blade section of the solid fan blade in a working state through optical fiber measurement;
and S6, carrying out difference on the real-time space coordinate matrix and the simulation space coordinate matrix to obtain a residual error matrix, and if the residual error matrix is greater than a threshold value, judging that the entity fan blade is in a fault state.
Equally dividing the solid fan blade into N +1 blade sections along the radial direction of an impeller of the solid fan blade, and measuring the section of each blade section, wherein the section measuring step comprises the following steps: equally dividing each blade section into M contour points along the circumferential direction of the section, and calculating to obtain the spatial coordinates of the M contour points to obtain the spatial coordinate matrix of the M contour points of each blade section of the entity fan blade in the non-operating state. The method comprises the steps that a first preset position is arranged on a solid fan blade, a first preset distance is reserved between the first preset position and the top end of the blade tip of the solid fan blade, the fan blade from the cylindrical blade root of the solid fan blade to the first preset position along the radial direction of an impeller is divided into N equal parts, and N +1 equal-divided blade sections are formed. The first preset distance is 0.05 m, namely the first preset position is 0.05 m away from the top end of the blade tip of the fan blade. In order to improve the accuracy, N is generally set to 15 or more. A schematic cross-sectional view of each blade of the fan blade shown in fig. 2.
The cross-sectional measurements of the blade cross-sections were made for N +1 blade cross-sections. The blade section measurement of the solid fan is carried out under the condition that the fan blade does not work, and the fan blade is in a state of not being subjected to external force. The blade section is equally divided into M contour points along the section circumferential direction on each blade section starting from the trailing edge. Calculating the radial position l of the impeller of each blade section by the formula (1)nRadial position l of the impellernThe distance from the center of the blade section to the blade root is ln, namely:
Figure DEST_PATH_IMAGE002AA
（1）；
wherein lnThe blade is the radial position of an impeller of the nth blade section, L is the distance from the center of the blade root of the fan blade to a first preset position, and N is 0-N.
Calculating the corresponding azimuth angle phi of each contour point by formula (2)m；
Figure DEST_PATH_IMAGE004AA
（2）；
Wherein M is the mth contour point on the blade section, and the value is between 0 and M, phimIs the azimuth angle, phi, of the mth profile point on the blade section relative to the center of the blade sectionmAnd performing M equal division between 0 and 360 degrees.
Measuring the profile coefficient R of each profile point of each blade sectionn(φm) The profile coefficient is used to represent the distance of a profile point to the center of the corresponding blade section.
The radial position l of the impeller of the blade sectionnAzimuth angle phi of each contour pointmAnd the contour coefficients of the M contour points form the space coordinates of the M contour points of the blade section, and the space coordinate set of the M contour points of each blade section is the space coordinate matrix C of the M contour points of each blade section of the entity fan blade in the non-operating staten:
Figure DEST_PATH_IMAGE006AA
（3）；
Wherein, CnIs a geometric matrix of contour points of the nth blade section, lnRadial position of the impeller at the section of the nth blademAzimuth angle, R, of the m-th contour pointn(φm) Is the profile factor of the mth profile point of the nth blade section.
All the profile coefficients of the N +1 blade sections of the solid fan blade form a profile coefficient matrix R of the solid fan blade in a non-working state, wherein R is as follows:
Figure DEST_PATH_IMAGE008AA
（4）；
wherein R isn(φm) Is the profile factor of the mth profile point of the nth blade section.
And constructing a fan blade digital twin model of a geometric structure corresponding to the entity fan blade, cutting a plurality of simulated blade sections between two adjacent blade sections in the fan blade digital twin model, calculating the spatial coordinates of M contour points of each simulated blade section according to the spatial coordinates of the M contour points of the two adjacent blade sections, and further obtaining a spatial coordinate matrix of any position of the entity fan blade in a non-working state. And constructing a fan blade digital twin model of the corresponding geometric structure of the fan blade through a computer-aided program. In the digital twin model of the fan blade, any plurality of simulated blade sections can be cut between two adjacent blade sections, for example, any simulated blade section R is cut between the nth blade section and the (n +1) th blade section, the simulated blade section R is equally divided into M contour points along the circumferential direction of the section, and the contour coefficient R of the mth contour point of the nth blade section is determined according to the contour coefficient R of the mth contour pointn(φm) And the profile coefficient R of the (n +1) th blade sectionn+1(φm) And the radial position l of the impeller according to the obtained simulated blade section rrCalculating the profile coefficient R of the mth profile point of the simulated blade section R by the formula (5)r(φm) Acquiring contour coefficients of all contour points of the section r of the simulated blade;
Figure DEST_PATH_IMAGE010AA
（5）；
wherein lnRadial position of the impeller at the section of the nth blade,/n+1The radial position of the impeller at the n +1 th blade section,
and in the same way, calculating to obtain the profile coefficients of all profile points of any simulated blade section r of the fan blade in the fan blade digital twin model.
Vane radial position l of blade section to be simulatedrM azimuth angles phi of contour pointsmAnd the contour coefficient R of M contour pointsr(φm) The spatial coordinates C (l) of the M contour points constituting the cross section of the simulated blader) Comprises the following steps:
Figure DEST_PATH_IMAGE012AA
（6）；
and further obtaining a space coordinate matrix of any position of the entity fan blade in the non-operating state.
And inputting the space coordinate matrix of any position of the entity fan blade in the non-working state and the material information of the fan blade into finite element analysis software, and calculating and simulating to obtain the mode coefficient matrixes of the first S modes of the fan blade in the working state under the respective states of shimmy, flap and torsion. The material information of the fan blade includes the density, Young's modulus and Poisson's ratio of the fan blade. And simulating and calculating a modal coefficient matrix of the fan blade in the respective states of shimmy, waving and torsion by using finite element analysis software.
The fan blade has multiple modes under the shimmy state, and multiple modes correspond a plurality of different natural frequencies, and according to natural frequency from low to high in proper order to the mode sequencing, select first S modes, the mode coefficient matrix of first S modes is:
Figure DEST_PATH_IMAGE014AA
（7）；
wherein f isi,m,nThe modal coefficient of the mth profile point of the nth fan blade section in the ith mode of the fan blade in the shimmy state is represented as fi,0,0The reference coefficient in the shimmy state is 1, i is 1-4, N is 0-N, and M is 0-M;
the fan blade has multiple modes in a waving state, the multiple modes correspond to multiple different natural frequencies, the modes are sequenced from low to high according to the natural frequencies, the first S modes are selected, and the mode coefficient matrixes of the first S modes are;
Figure DEST_PATH_IMAGE016AA
（8）；
wherein e isj,m,nThe reference coefficient of the mth contour point of the nth fan blade section in the jth mode in the flapping state of the fan blade is represented, j takes the value of 1-4, and ej,0,0The reference coefficient in the waving state is 1, N is 0-N, and M is 0-M.
The fan blade has multiple modes in the bending state, the multiple modes correspond to multiple different natural frequencies, the modes are sequenced from low to high according to the natural frequencies, the first S modes are selected, and the mode coefficient matrix of the first S modes is as follows:
Figure DEST_PATH_IMAGE018AA
（9）；
wherein, tk,m,nThe modal coefficient of the mth profile point of the nth fan blade section under the kth modal in the bending state of the fan blade is represented, the k value is 1-4, and t isk,0,0The reference coefficient in the bending state is 1, N is 0-N, and M is 0-M. Each mode contains (N +1) × (M +1) coefficients below. The values of the other elements in each mode coefficient matrix are relative sizes with respect to the mode reference coefficient. The value range of S is usually 3-6, and the default value is 4.
And calculating to obtain a simulation space coordinate matrix of M contour points of each blade section of the fan blade in a working state according to the mode coefficient matrixes of the first S modes of the fan blade in the respective states of shimmy, flapping and torsion. Since the spatial coordinates of the contour points are represented by cylindrical coordinates, only the contour coefficients of the contour points can be calculated in subsequent calculations. The simulation contour coefficient matrix of the M contour points of each blade section is a linear combination equation of the modal coefficient matrix of the first S modes of the fan blade in the respective states of shimmy, flapping and torsion, and the linear combination equation is as follows:
Figure DEST_PATH_IMAGE020A
（10）；
wherein, ai, bj,ckAnd is a linear equation coefficient.
For a normally operating fan blade, the matrix of simulated contour coefficients for the contour points can always be decomposed into a linear combination of 3 × S modes described by equations (7), (8), (9).
Optical fibers are arranged on the solid fan blades, and a real-time space coordinate matrix of all contour points of each blade of the solid fan blades in a working state is obtained through optical fiber measurement. As shown in the schematic optical fiber arrangement diagram of fig. 3, a distributed dynamic strain sensor based on brillouin scattering is deployed in a fan blade, and a signal is obtained by measuring the sensor and is demodulated to obtain real-time space coordinates of M contour points of N +1 blade sections of the physical fan blade in a working state. Since the spatial coordinates of the contour points are represented by cylindrical coordinates, only the contour coefficients of the contour points can be calculated in subsequent calculations. All the profile coefficients of the N +1 blade sections of the solid fan blade form a real-time profile coefficient matrix of the solid fan blade in a working state:
Figure DEST_PATH_IMAGE022A
（11）。
and performing difference on the real-time space coordinate matrix and the simulation space coordinate matrix to obtain a residual error matrix, and if the residual error matrix is greater than a threshold value, judging that the entity fan blade is in a fault state. The residual matrix res is:
Figure DEST_PATH_IMAGE024A
（12）。
if the residual matrix is obtained, a in equation (10) needs to be solvedi, bj,ck. Solving a in equation (10) because the profile coefficient of the profile points of the 3S modal characterization fan blade is selectedi, bj,ck3 × S equations are needed, and the most representative feature points need to be selected for solving, so as to reduce errors. According to the real-time profile coefficient matrix of the solid fan blade and the blade of the fan blade in the non-working stateCalculating the profile coefficient of the profile point of the blade section, and calculating the displacement offset D of each profile point in the N +1 blade sectionsm,n：
Figure DEST_PATH_IMAGE026A
（13）；
Will calculate all Dm,nSequentially arranging from large to small, and sequentially selecting 3S D from the maximum valuem,n；
3S Dm,nSubstituting the corresponding real-time contour coefficient into the equation (10), and solving to obtain a linear equation coefficient a1,a2,…,aS,b1,b2,…,bS,c1,c2,…,cS；
Substituting the solved linear equation coefficient into an equation (12) to obtain a residual error matrix res, obtaining absolute values of all elements in the residual error matrix res, if the absolute values are larger than a threshold value, judging that the entity fan blade is in a fault state, otherwise, judging that the entity fan blade is in a normal state. The threshold value is typically set to 0.1.
In an embodiment of the present invention shown in fig. 4, the present invention provides a fan blade fault analysis based on a modal decomposition algorithm, and the system includes:
a section measuring module 40, configured to equally divide the physical fan blade into N +1 blade sections along a radial direction of an impeller of the physical fan blade, and perform section measurement on each blade section, where the section measuring step includes: equally dividing each blade section into M contour points along the circumferential direction of the section, and calculating to obtain the spatial coordinates of the M contour points to obtain a spatial coordinate matrix of the M contour points of each blade section of the entity fan blade in a non-operating state;
a digital twin model module 41, configured to construct a fan blade digital twin model of a geometric structure corresponding to the physical fan blade, intercept multiple simulated blade sections between two adjacent blade sections in the fan blade digital twin model, calculate spatial coordinates of M contour points of each simulated blade section according to spatial coordinates of M contour points of each of the two adjacent blade sections, and further obtain a spatial coordinate matrix of any position of the physical fan blade in an inoperative state;
the finite element analysis module 42 is configured to input the spatial coordinate matrix of any position of the physical fan blade in the non-operating state and material information of the fan blade into finite element analysis software, and calculate and simulate to obtain modal coefficient matrices of the first S modes of the fan blade in the operating state under the respective states of shimmy, flapping, and torsion;
the calculation module 43 is configured to calculate a simulation space coordinate matrix of all contour points of each blade of the fan blade in a working state according to a mode coefficient matrix of the first S modes of the fan blade in respective states of shimmy, flapping, and torsion;
the optical fiber measurement module 44 is used for arranging optical fibers on the solid fan blade, and obtaining a real-time space coordinate matrix of all contour points of each blade of the solid fan blade in a working state through optical fiber measurement
And the judging module 45 is configured to perform a difference between the real-time spatial coordinate matrix and the simulated spatial coordinate matrix to obtain a residual matrix, and if the residual matrix is greater than a threshold, determine that the physical fan blade is in a fault state.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (10)

1. A fan blade fault analysis method based on a modal decomposition algorithm is characterized by comprising the following steps:
s1, equally dividing the solid fan blade into N +1 blade sections along the radial direction of an impeller of the solid fan blade, and measuring the section of each blade section, wherein the section measuring step comprises the following steps: equally dividing each blade section into M contour points along the circumferential direction of the section, and calculating to obtain the spatial coordinates of the M contour points to obtain a spatial coordinate matrix of the M contour points of each blade section of the entity fan blade in a non-operating state;
s2, constructing a fan blade digital twin model of a geometric structure corresponding to the entity fan blade, intercepting a plurality of simulation blade sections between two adjacent blade sections in the fan blade digital twin model, and calculating the spatial coordinates of M contour points of each simulation blade section according to the spatial coordinates of the M contour points of the two adjacent blade sections so as to obtain a spatial coordinate matrix of any position of the entity fan blade in a non-working state;
s3, inputting the space coordinate matrix of any position of the entity fan blade in the non-operating state and the material information of the fan blade into finite element analysis software, and calculating and simulating to obtain the mode coefficient matrix of the first S modes of the fan blade in the operating state under the respective states of shimmy, flap and torsion;
s4, calculating to obtain a simulation space coordinate matrix of M contour points of each blade section of the fan blade in a working state according to the mode coefficient matrixes of the first S modes of the fan blade in the respective states of shimmy, waving and torsion;
s5, arranging optical fibers on the solid fan blade, and obtaining a real-time space coordinate matrix of M contour points of each blade section of the solid fan blade in a working state through optical fiber measurement;
and S6, carrying out difference on the real-time space coordinate matrix and the simulation space coordinate matrix to obtain a residual error matrix, and if the residual error matrix is greater than a threshold value, judging that the entity fan blade is in a fault state.
2. The wind turbine blade fault analysis method based on modal decomposition algorithm according to claim 1, wherein the step S1 includes:
the method comprises the steps that a first preset position is arranged on a solid fan blade, a first preset distance is reserved between the first preset position and the top end of the blade tip of the solid fan blade, the fan blade from the cylindrical blade root of the solid fan blade to the first preset position along the radial direction of an impeller is divided into N equal parts, and N +1 equal-divided blade sections are formed.
3. The wind turbine blade fault analysis method based on modal decomposition algorithm according to claim 1, wherein the step S1 further comprises:
equally dividing the blade section into M contour points along the section circumferential direction from the trailing edge on each blade section;
calculating the radial position ln of the impeller of each blade section through a formula (1);
Figure DEST_PATH_IMAGE001
（1）；
wherein lnThe radial position of an impeller of the section of the nth blade is shown, L is the distance from the center of the blade root of the fan blade to a first preset position, and N is 0-N;
calculating the corresponding azimuth angle phi of each contour point by formula (2)m；
Figure DEST_PATH_IMAGE002
（2）；
Wherein M represents the serial number of the mth contour point on the blade section, and the value is between 0 and M, phimIs the azimuth angle, phi, of the mth profile point on the blade section relative to the center of the blade sectionmPerforming M equal division between 0 and 360 degrees;
measuring the profile coefficient R of each profile point of each blade sectionn(φm) The profile coefficient is used for representing the distance from a profile point to the center of the corresponding blade section;
the radial position l of the impeller of the blade sectionnAzimuth angle phi of each contour pointmAnd the contour coefficients of the M contour points form the space coordinates of the M contour points of the blade section, and M wheels of each blade section are obtainedEstablishing a space coordinate matrix C of M contour points of each blade section of the entity fan blade in a non-operating staten：
Figure DEST_PATH_IMAGE003
（3）；
Wherein, CnIs a geometric matrix of contour points of the nth blade section, lnRadial position of the impeller at the section of the nth blademAzimuth angle, R, of the m-th contour pointn(φm) Is the profile factor of the mth profile point of the nth blade section.
4. The wind turbine blade fault analysis method based on modal decomposition algorithm according to claim 3, wherein the step S1 further comprises:
all the profile coefficients of the N +1 blade sections of the solid fan blade form a profile coefficient matrix R of the solid fan blade in a non-working state:
Figure DEST_PATH_IMAGE004
（4）；
wherein R isn(φm) Is the profile factor of the mth profile point of the nth blade section.
5. The wind turbine blade fault analysis method based on modal decomposition algorithm according to claim 4, wherein the step S2 includes:
any simulated blade section R is cut between the nth blade section and the (n +1) th blade section, the simulated blade section R is equally divided into M contour points along the circumferential direction of the section, and the contour coefficient R of the mth contour point of the nth blade section is determined according to the contour coefficient R of the mth contour pointn(φm) And the profile coefficient R of the (n +1) th blade sectionn+1(φm) And the radial position l of the impeller according to the obtained simulated blade section rrCalculated by the formula (5) to obtain theProfile coefficient R of mth profile point of simulated blade section Rr(φm) Acquiring contour coefficients of all contour points of the section r of the simulated blade;
Figure DEST_PATH_IMAGE005
（5）；
wherein lnRadial position of the impeller at the section of the nth blade,/n+1The impeller radial position of the (n +1) th blade section;
by analogy, calculating the contour coefficients of all contour points of any simulated blade section r of the fan blade in the fan blade digital twin model;
vane radial position l of blade section to be simulatedrM azimuth angles phi of contour pointsmAnd the contour coefficient R of M contour pointsr(φm) The spatial coordinates C (l) of the M contour points constituting the cross section of the simulated blader)：
Figure DEST_PATH_IMAGE006
（6）；
And obtaining a space coordinate matrix of any position of the entity fan blade in the non-operating state.
6. The wind turbine blade fault analysis method based on modal decomposition algorithm according to claim 5, wherein the step S3 includes:
the fan blade has multiple modes under the shimmy state, and multiple modes correspond a plurality of different natural frequencies, and according to natural frequency from low to high in proper order to the mode sequencing, select first S modes, the mode coefficient matrix of first S modes is:
Figure DEST_PATH_IMAGE007
（7）；
wherein f isi,m,nRepresenting the ith mode of the fan blade in the shimmy stateModal coefficient of the mth profile point of the nth blade section in the state, fi,0,0The reference coefficient in the shimmy state is 1, i is 1-S, N is 0-N, and M is 0-M;
the fan blade has multiple modality at the state of waving, and multiple modality corresponds a plurality of different natural frequencies, sorts the modality according to natural frequency from low to high in proper order, selects first S modalities, the mode coefficient matrix of first S modalities is:
Figure DEST_PATH_IMAGE008
（8）；
wherein e isj,m,nThe reference coefficient of the mth contour point of the nth fan blade section in the jth mode in the flapping state of the fan blade is represented, j takes the value of 1-S, ej,0,0The reference coefficient in the waving state is 1, N is 0-N, and M is 0-M;
the fan blade has multiple modes in the bending state, the multiple modes correspond to multiple different natural frequencies, the modes are sequenced from low to high according to the natural frequencies, the first S modes are selected, and the mode coefficient matrix of the first S modes is as follows:
Figure DEST_PATH_IMAGE009
（9）；
wherein, tk,m,nThe modal coefficient of the mth profile point of the nth fan blade section under the kth modal in the bending state of the fan blade is represented, wherein k is 1-S, and tk,0,0The reference coefficient in the bending state is 1, N is 0-N, and M is 0-M.
7. The wind turbine blade fault analysis method based on modal decomposition algorithm according to claim 6, wherein the step S3 includes:
the simulation contour coefficient matrix of the M contour points of each blade section is a linear combination equation of the modal coefficient matrix of the first S modes of the fan blade in the respective states of shimmy, flapping and torsion, and the linear combination equation is as follows:
Figure DEST_PATH_IMAGE010
（10）；
wherein, ai, bj, ckIs a linear equation coefficient;
the step S4 includes:
all the profile coefficients of the N +1 blade sections of the solid fan blade form a real-time profile coefficient matrix of the solid fan blade in a working state:
Figure DEST_PATH_IMAGE011
（11）。
8. the wind turbine blade fault analysis method based on modal decomposition algorithm according to claim 7, wherein the step S6 includes:
the residual matrix res is:
Figure DEST_PATH_IMAGE012
（12）。
9. the wind turbine blade fault analysis method based on modal decomposition algorithm according to claim 8, wherein the step S6 includes:
calculating the displacement offset D of each contour point in the N +1 blade sections according to the real-time contour coefficient matrix of the entity fan blade and the contour coefficient of the contour point of the blade section of the fan blade in the non-operating statem,n：
Figure DEST_PATH_IMAGE013
（13）；
Will calculate all Dm,nArranged from large to small in sequence, starting from the maximumSequentially selecting 3 x S Dm,n；
3S Dm,nSubstituting the corresponding real-time contour coefficient into the equation (10), and solving to obtain a linear equation coefficient a1,a2,…,aS,b1,b2,…,bS,c1,c2,…,cS；
Substituting the solved linear equation coefficient into an equation (12) to obtain a residual error matrix res;
after the absolute values of all the elements in the residual error matrix res are obtained, if the absolute values are larger than a threshold value, the entity fan blade is judged to be in a fault state, otherwise, the entity fan blade is judged to be in a normal state.
10. A fan blade fault analysis system based on a modal decomposition algorithm, the system comprising:
the cross section measuring module is used for equally dividing the solid fan blade into N +1 blade cross sections along the radial direction of an impeller of the solid fan blade, and measuring the cross section of each blade cross section, wherein the cross section measuring step comprises the following steps: equally dividing each blade section into M contour points along the circumferential direction of the section, and calculating to obtain the spatial coordinates of the M contour points to obtain a spatial coordinate matrix of the M contour points of each blade section of the entity fan blade in a non-operating state;
the digital twin model module is used for constructing a fan blade digital twin model of a geometric structure corresponding to the entity fan blade, a plurality of simulated blade sections are intercepted between two adjacent blade sections in the fan blade digital twin model, and the spatial coordinates of M contour points of each simulated blade section are calculated according to the spatial coordinates of the M contour points of the two adjacent blade sections, so that a spatial coordinate matrix of any position of the entity fan blade in a non-working state is obtained;
the finite element analysis module is used for inputting the space coordinate matrix of any position of the entity fan blade in the non-working state and the material information of the fan blade into finite element analysis software, and calculating and simulating to obtain modal coefficient matrixes of the first S modes of the fan blade in the working state under the respective states of shimmy, flap and torsion;
the calculation module is used for calculating and obtaining a simulation space coordinate matrix of M contour points of each blade section of the fan blade in a working state according to the mode coefficient matrixes of the first S modes of the fan blade in the respective states of shimmy, flapping and torsion;
the optical fiber measurement module is used for arranging optical fibers on the solid fan blade and obtaining a real-time space coordinate matrix of M contour points of each blade section of the solid fan blade in a working state through optical fiber measurement;
and the judging module is used for carrying out difference on the real-time space coordinate matrix and the simulation space coordinate matrix to obtain a residual error matrix, and if the residual error matrix is greater than a threshold value, judging that the entity fan blade is in a fault state.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114992063A (en) * 2022-05-06 2022-09-02 国能信控互联技术有限公司 Automatic fan blade fault detection method and system
CN115450858A (en) * 2022-10-18 2022-12-09 山东大学 Fan blade state detection method and system based on digital twinning

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102564750A (en) * 2011-12-27 2012-07-11 中国科学院工程热物理研究所 Method for correcting blade modal testing result of horizontal axis wind turbine
US20150176570A1 (en) * 2013-12-20 2015-06-25 Siemens Aktiengesellschaft Detecting a pitch angle adjustment fault
CN111091298A (en) * 2019-12-20 2020-05-01 华北电力大学 Wind power plant flow field coupling characteristic evaluation and intelligent grouping method and system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102564750A (en) * 2011-12-27 2012-07-11 中国科学院工程热物理研究所 Method for correcting blade modal testing result of horizontal axis wind turbine
US20150176570A1 (en) * 2013-12-20 2015-06-25 Siemens Aktiengesellschaft Detecting a pitch angle adjustment fault
CN111091298A (en) * 2019-12-20 2020-05-01 华北电力大学 Wind power plant flow field coupling characteristic evaluation and intelligent grouping method and system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
薄翠梅等: "基于多残差描述的鲁棒故障诊断方法", 《科技通报》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114992063A (en) * 2022-05-06 2022-09-02 国能信控互联技术有限公司 Automatic fan blade fault detection method and system
CN115450858A (en) * 2022-10-18 2022-12-09 山东大学 Fan blade state detection method and system based on digital twinning

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