CN-122021152-A - Flexible photovoltaic bracket wind load analysis method

CN122021152ACN 122021152 ACN122021152 ACN 122021152ACN-122021152-A

Abstract

The invention discloses a wind load analysis method of a flexible photovoltaic bracket, and relates to the technical field of photovoltaic brackets. The method comprises the steps of constructing a finite element model, generating a space pulsation wind speed field through a linear filtering method based on a Darwort spectrum, carrying out wind speed simulation on the finite element model, converting the space pulsation wind speed field into photovoltaic panel pulsation wind pressure time-course data, obtaining the complete wind pressure field time-course data of the photovoltaic panel through an interpolation method after the photovoltaic panel pulsation wind pressure time-course data are subjected to intrinsic orthogonal decomposition, obtaining a wind load type coefficient through a numerical wind tunnel method, obtaining the complete pulsation wind load time-course data of the photovoltaic panel by combining the complete wind pressure field time-course data of the photovoltaic panel and the wind load type coefficient, inputting the complete pulsation wind load time-course data into the finite element model, calculating a displacement wind vibration coefficient and each cable unit generalized internal force wind vibration coefficient through a peak factor method and a generalized internal force wind vibration coefficient method, obtaining the integral internal force wind vibration coefficient through an envelope method, and obtaining wind load by combining the displacement wind vibration coefficient, the integral internal force wind vibration coefficient and the wind load type coefficient.

Inventors

ZHA DAWEI
LIU QUNYANG
LIU BINGBING
HUANG QIBAI

Assignees

武汉联动设计股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260126

Claims (10)

1. A wind load analysis method of a flexible photovoltaic bracket is characterized by comprising the following steps: s1, constructing a flexible photovoltaic support finite element model, adopting a linear filtering method based on a Darwort spectrum to generate a space pulsation wind speed field, carrying out wind speed simulation on the flexible photovoltaic support finite element model through the space pulsation wind speed field, carrying out wind pressure conversion through a Bernoulli principle, and calculating to obtain pulsation wind pressure time interval data of a photovoltaic panel; S2, decomposing the pulse wind pressure time-course data of the photovoltaic panel through an intrinsic orthogonal decomposition technology to obtain a wind pressure spatial mode of the photovoltaic panel; S3, carrying out three-dimensional modeling on a photovoltaic array group to obtain a photovoltaic array group model, carrying out hydrodynamic simulation on the photovoltaic array group model through a numerical wind tunnel method to obtain wind pressure distribution data of a photovoltaic panel, and calculating the wind pressure distribution data of the photovoltaic panel through a partition weighted average method to obtain a wind load type coefficient; S4, inputting the complete pulsating wind load time course data of the photovoltaic panel into the flexible photovoltaic bracket finite element model to obtain flexible photovoltaic bracket displacement time course data and cable unit internal force time course data, calculating the flexible photovoltaic bracket displacement time course data through a peak factor method to obtain displacement wind vibration coefficients, and calculating wind vibration coefficients of the cable units to obtain generalized internal force wind vibration coefficients of the cable units; s5, calculating generalized internal force wind vibration coefficients of each cable unit through an enveloping method to obtain an integral internal force wind vibration coefficient, and calculating the wind load of the flexible photovoltaic bracket through combining the displacement wind vibration coefficient, the integral internal force wind vibration coefficient and the wind load body type coefficient.
2. The method for analyzing wind load of a flexible photovoltaic bracket according to claim 1, wherein the method for generating a spatial pulsation wind speed field by adopting a linear filtering method based on a Darwiniature Boud spectrum comprises the following specific steps: A linear filtering method based on a Darwin Bode spectrum is adopted to generate a space pulsation wind speed field, and a related function calculation formula of a random process is as follows: ; Wherein f is the frequency of the fluctuating wind speed, Is a related function of the fluctuating wind speed, in units of (m/s) 2 , For a pulsatile wind speed power spectrum, Representing the time interval between two wind pressure signals in seconds; when the fluctuating wind speed simulation based on the linear filtering method is carried out, the autoregressive coefficient needs to be determined The equation set of (2) is: ; Wherein, the For a fluctuating wind speed at t= Is used as a correlation function of the (c), j=1, 2,..p, The order of the AR model is given, and m is the index of the order of the AR model; variance of white noise of AR model The method comprises the following steps: ; Wherein, the Is the variance of the gaussian white noise N (t), As the variance of the pulsating wind velocity, , Autoregressive coefficients for the AR model; adopting an AR linear filtering method, and adopting a pulsation wind speed time interval expression at the moment t as follows: ; Wherein, the Is the fluctuating wind speed at the moment t, Is the autoregressive coefficient of the AR model, For the order of the AR model, For a fluctuating wind speed m times before time t, For the time step of the pulsating wind speed, Mean value 0, variance AR model white noise of (c).
3. The method for analyzing wind load of the flexible photovoltaic support according to claim 2, wherein wind pressure conversion is performed by the Bernoulli principle, pulsating wind pressure time-course data of the photovoltaic panel are obtained through calculation, and the method comprises the following steps: Wind pressure conversion is carried out through Bernoulli principle, and pulsating wind pressure time interval data of the photovoltaic panel are obtained through calculation: ; Wherein, the For the air density, here 1.225kg/m3 was taken, Is the fluctuating wind speed at the moment t, The time course of the pulsating wind pressure of the photovoltaic panel at the time t is given.
4. The method for analyzing wind load of the flexible photovoltaic support according to claim 3, wherein the decomposing of the pulsating wind pressure time course data of the photovoltaic panel by the intrinsic orthogonal decomposition technique to obtain a wind pressure spatial mode of the photovoltaic panel comprises the following steps: decomposing the pulsating wind pressure time course data of the photovoltaic panel by an intrinsic orthogonal decomposition technology to obtain a wind pressure space mode of the photovoltaic panel; The wind pressure field can be expressed as , wherein, Representing spatial position The wind pressure time course at the point(s), Is the number of wind pressure time-course vectors, An index of eigenmodes; constructing a wind pressure field covariance matrix: ; Wherein, the Is the wind pressure time course at the moment t Is used to determine the transposed matrix of (a), Is a wind pressure field covariance matrix; The characteristic equation of the wind pressure field covariance matrix is as follows: ; Wherein, the For the f-th eigenvalue of the covariance matrix C, Representing the eigenvalue of the order mode as the corresponding eigenvector; Solving a characteristic equation of a covariance matrix of the wind pressure field to obtain a characteristic value And corresponding feature vector Combining all the characteristic vectors into a photovoltaic panel wind pressure space mode, wherein the wind pressure space mode is as follows: , wherein, Is a wind pressure space mode of the photovoltaic panel.
5. The method for analyzing wind load of the flexible photovoltaic support according to claim 4, wherein the method for filling the wind pressure field of the photovoltaic panel by interpolation based on the wind pressure spatial mode of the photovoltaic panel to obtain complete wind pressure field time-course data of the photovoltaic panel comprises the following steps: the column vector of the wind pressure space mode of the photovoltaic panel is the intrinsic mode of the wind pressure field, and the main coordinate matrix is obtained through projection: ; Wherein, the A (t) represents a time weight coefficient of the wind pressure field on an intrinsic mode corresponding to the f-th characteristic value; the energy ratio contained in the eigenvalue corresponding to each eigenvalue is calculated as follows: ; Wherein, the The energy contained in the eigenvector corresponding to the f-th eigenvalue is the proportion of the total turbulence energy, For the f-th eigenvalue of the covariance matrix C, The total turbulence energy of the wind pressure field is characterized, The number of wind pressure time course vectors; the intrinsic mode at the predicted point is obtained by interpolation through the selected intrinsic mode, and the complete wind pressure field of the photovoltaic panel is restored by the intrinsic mode and the main coordinates: ; Wherein, the The time course data of the complete wind pressure field of the photovoltaic panel is calculated ) As the coordinates of the predicted point of interest, For predicting the wind pressure time course at the point, The principal coordinate vector after interception, namely the principal coordinate matrix of the leading M-order dominant mode, Is the spatial modal vector at the predicted point.
6. The method for analyzing wind load of the flexible photovoltaic bracket according to claim 5, wherein the method for calculating wind pressure distribution data of the photovoltaic panel by a partition weighted average method to obtain a wind load body type coefficient comprises the following specific steps: Calculating the wind pressure distribution data of the photovoltaic panel by a partition weighted average method to obtain a wind load body type coefficient, and calculating an instantaneous wind pressure coefficient of a monitoring point: ; Wherein, the For the instantaneous wind pressure coefficient at monitoring point a, , The wind pressure of the upper surface and the lower surface of the monitoring point a at the time t is respectively, For an air density of 1.225kg/m 3 , Is the average horizontal wind speed at the reference altitude (10 m); The average wind pressure coefficient is: ; Wherein, the As an average wind pressure coefficient of the whole photovoltaic panel, The unit is m2, the unit is the total number of the monitoring points, Is the total area of the photovoltaic panel; the wind load body type coefficients are: ; Wherein, the Is the wind pressure height variation coefficient, = Z is the flexible photovoltaic ground clearance height, the unit is m, The correction coefficient of the wind pressure distribution unevenness of the surface of the structure is reflected as the wind load body type coefficient.
7. The method for analyzing wind load of the flexible photovoltaic bracket according to claim 6, wherein the calculating of the complete wind pressure field time course data of the photovoltaic panel through the wind load formula to obtain the complete pulsating wind load time course data of the photovoltaic panel comprises the following specific steps: based on the wind load body type coefficient, calculating the complete wind pressure field time course data of the photovoltaic panel through a wind load formula to obtain the complete pulsating wind load time course data of the photovoltaic panel: ; Wherein, the Is a model coefficient of the wind load, For the area of the photovoltaic panel, For the complete pulsating wind load time course data of the photovoltaic panel, For the air density, here 1.225kg/m3 was taken, The average wind speed of the height of the photovoltaic support is v (t) is the fluctuating wind speed at the moment t.
8. The method for analyzing the wind load of the flexible photovoltaic bracket according to claim 7, wherein the method for calculating the displacement time course data of the flexible photovoltaic bracket by a peak factor method to obtain the displacement wind vibration coefficient comprises the following specific steps: calculating displacement time course data of the flexible photovoltaic support by a peak factor method to obtain a displacement wind vibration coefficient: ; Wherein, the Is the wind vibration coefficient of the displacement, For static displacement caused by average wind, the static force analysis is carried out on the flexible photovoltaic bracket through ANSYS software, Is the mean square error of the pulsating wind displacement.
9. The method for analyzing wind load of the flexible photovoltaic bracket according to claim 8, wherein the generalized internal force wind vibration coefficient of each cable unit is obtained by wind vibration coefficient calculation on the internal force time course data of the cable unit, and the method comprises the following specific steps: calculating the mean square error of the pulsating wind displacement response: ; Wherein, the The mean square error of the displacement response of the pulsating wind is calculated, u is the displacement caused by the pulsating wind, s is the index of the time step, N is the time step number, and N is 1000; the mean value of the force in the cable is calculated, the calculation formula of the mean value of the force in the cable is as follows: ; Wherein, the N is the time step number, which is the mean value of the force in the cable, the value is 1000, Is the internal force time course of the cable unit of the b time step; the standard deviation of the mean value of the force in the cable is: ; Wherein, the Is the standard deviation of the mean value of the force in the cable, N is the time step number and the value is 1000; The generalized internal force wind vibration coefficient formula of each cable unit is as follows: ; Wherein, the Is the internal force of the cable under the action of static wind load, Is the mean value of the force in the cable, Is set to a peak factor, set to 2.5, Is the standard deviation of the mean value of the force in the cable, Is a generalized internal force wind vibration coefficient.
10. The method for analyzing the wind load of the flexible photovoltaic bracket according to claim 9, wherein the wind load of the flexible photovoltaic bracket is calculated by combining the displacement wind vibration coefficient, the integral internal force wind vibration coefficient and the wind load body type coefficient, and the method comprises the following specific steps of: and calculating the wind load of the flexible photovoltaic bracket by combining the displacement wind vibration coefficient, the integral internal force wind vibration coefficient and the wind load body type coefficient, wherein the calculation formula of the final wind load of the flexible photovoltaic bracket is as follows: ; Wherein, the Is the wind load value of the flexible photovoltaic bracket, Is the integral internal force wind vibration coefficient, Is the wind vibration coefficient of the displacement, Is a model coefficient of the wind load, Is the basic wind pressure.

Description

Flexible photovoltaic bracket wind load analysis method Technical Field The invention relates to the technical field of photovoltaic supports, in particular to a wind load analysis method of a flexible photovoltaic support. Background The flexible photovoltaic support is widely applied to complex terrains by virtue of the advantages of large span and light weight, physical connection is realized between the photovoltaic panel and the supporting structure through the cable unit, one end of the flexible photovoltaic support is anchored on the boundary of the supporting structure, the other end of the flexible photovoltaic support bears the dead weight and external load of the photovoltaic panel, but the low-damping and high-flexibility structural characteristics of the flexible photovoltaic support lead to extremely sensitive wind load, wind-induced vibration not only induces great displacement, but also generates significant nonlinear dynamic response in the cable unit, and the cable internal force presents non-Gaussian distribution characteristics under the action of turbulence and geometric nonlinear coupling, so that the design of wind resistance safety and economy of the structure is severely challenged. The existing method is mainly an equivalent static force method based on Gaussian assumption, the method converts the pulsating wind load into static force equivalent load, a support structure response extremum under the equivalent load is solved by adopting static force analysis, a displacement wind vibration coefficient is calculated based on the support structure response extremum, and the wind load of the flexible photovoltaic support is analyzed by the displacement wind vibration coefficient. However, the equivalent static force method based on Gaussian assumption is only suitable for displacement response of Gaussian distribution, the internal force response of the flexible photovoltaic bracket cable structure presents obvious non-Gaussian characteristics, and the cable force extremum is underestimated by directly applying the displacement wind vibration coefficient, so that the estimated value of wind load is lower, the structural design depends on potential safety hazards, and the prior art lacks a special wind vibration coefficient for the cable structure non-Gaussian internal force response. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a wind load analysis method of a flexible photovoltaic bracket, which solves the problems existing in the background art. In order to achieve the purpose, the invention is realized by the following technical scheme that the wind load analysis method of the flexible photovoltaic bracket comprises the following steps: s1, constructing a flexible photovoltaic support finite element model, adopting a linear filtering method based on a Darwort spectrum to generate a space pulsation wind speed field, carrying out wind speed simulation on the flexible photovoltaic support finite element model through the space pulsation wind speed field, carrying out wind pressure conversion through a Bernoulli principle, and calculating to obtain pulsation wind pressure time interval data of a photovoltaic panel; S2, decomposing the pulse wind pressure time-course data of the photovoltaic panel through an intrinsic orthogonal decomposition technology to obtain a wind pressure spatial mode of the photovoltaic panel; S3, carrying out three-dimensional modeling on a photovoltaic array group to obtain a photovoltaic array group model, carrying out hydrodynamic simulation on the photovoltaic array group model through a numerical wind tunnel method to obtain wind pressure distribution data of a photovoltaic panel, and calculating the wind pressure distribution data of the photovoltaic panel through a partition weighted average method to obtain a wind load type coefficient; S4, inputting the complete pulsating wind load time course data of the photovoltaic panel into the flexible photovoltaic bracket finite element model to obtain flexible photovoltaic bracket displacement time course data and cable unit internal force time course data, calculating the flexible photovoltaic bracket displacement time course data through a peak factor method to obtain displacement wind vibration coefficients, and calculating wind vibration coefficients of the cable units to obtain generalized internal force wind vibration coefficients of the cable units; s5, calculating generalized internal force wind vibration coefficients of each cable unit through an enveloping method to obtain an integral internal force wind vibration coefficient, and calculating the wind load of the flexible photovoltaic bracket through combining the displacement wind vibration coefficient, the integral internal force wind vibration coefficient and the wind load body type coefficient. Preferably, the generating the spatial pulsating wind speed field by using a linear filtering method based on the D