Wind turbine generator blade aeroelastic coupling model with pre-bent appearance taken into account and modeling method

Abstract

The invention provides a wind power blade aeroelastic coupling modeling method considering a pre-bending shape, which comprises the following steps of: establishing a finite element kinetic equation of a geometric precise beam structure of a pre-bending blade and solving to obtain the section speed of the blade; calculating the inflow velocity according to the section velocity of the blade; calculating a lift coefficient after dynamic stall of the blade; establishing an unsteady aerodynamic load calculation equation according to the inflow velocity and the lift coefficient after dynamic stall of the blade; and constructing a pre-bent blade aeroelastic coupling model according to the unsteady aerodynamic load calculation equation. The method can solve the technical problems that a modeling method in the prior art cannot accurately describe nonlinear deformation of the blade, the continuity of a blade model is poor, the number of calculation units is too large, the calculation efficiency is low, and the modeling method is not suitable for the long flexible blade.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to an aeroelastic coupling model of a wind turbine blade taking into account a pre-bent shape and a modeling method. Background Art

[0002] After wind power entered the era of parity, cost reduction and efficiency improvement are the key to the development of the industry. Improving the energy capture of wind turbines is an effective way to reduce the cost of power generation, and increasing the length of blades can increase the power generation. As the length of the blade increases, the aeroelastic coupling effect of the blade becomes more obvious, resulting in increased deformation of the blade, making it more difficult to ensure the safe distance between the blade tip and the tower, and making it more likely to sweep the tower; at the same time, it increases the probability of an unfavorable phase between aerodynamic force and elastic deformation, which can easily lead to aeroelastic instability of the blade.

[0003] In order to increase the clearance between the blade tip and the tower and avoid the blade sweeping the tower, the blades are usually pre-bent during the design of large-megawatt wind turbine blades. The pre-bent shape of the blade will change the aerodynamic layout of the blade, thereby affecting the overall aerodynamic performance of the blade. Therefore, establishing an aeroelastic coupling model of pre-bent blades and studying the influence of the pre-bent shape of the blade on the aeroelastic performance are of great significance for guiding the design of wind turbine blades. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes an aeroelastic coupling model and modeling method for wind turbine blades taking into account the pre-bent shape, so as to solve the technical problems existing in the prior art, such as the inability to accurately describe the nonlinear deformation of the blades, poor continuity of the blade model, too many calculation units, low calculation efficiency, and unsuitability for long and flexible blades.

[0005] The technical solution adopted by the present invention is as follows:

[0006] In a first aspect, a method for aeroelastic coupling modeling of a wind turbine blade taking into account a pre-bent shape is provided, comprising the following steps:

[0007] The finite element dynamic equations of the geometrically accurate beam structure of the pre-bent blade are established and solved to obtain the cross-sectional velocity of the blade;

[0008] Calculate the inflow velocity based on the blade's cross-sectional velocity;

[0009] Calculate the lift coefficient of the blade after dynamic stall;

[0010] The unsteady aerodynamic load calculation equation is established based on the inflow velocity and the lift coefficient of the blade after dynamic stall.

[0011] The aeroelastic coupling model of pre-bent blades is constructed based on the unsteady aerodynamic load calculation equation.

[0012] Furthermore, the finite element dynamic equations of the geometrically accurate beam structure of the pre-bent blade are established, including:

[0013] Calculate the mass matrix, stiffness matrix and energy matrix of each unit of the blade and assemble them according to the number of degrees of freedom to obtain the overall mass matrix, overall stiffness matrix and overall energy matrix of the blade;

[0014] The finite element dynamic equations of the geometrically accurate beam structure of the pre-bent blade are established based on the blade's overall mass matrix, overall stiffness matrix, overall energy matrix and external load matrix.

[0015] Furthermore, the inflow velocity is calculated based on the cross-sectional velocity of the blade, and the inflow velocity is equal to the sum of the local velocity of the free stream, the cross-sectional velocity of the blade, and the induced velocity of the blade.

[0016] Furthermore, when calculating the inflow velocity, the dynamic wake model can be used to correct the induced velocity of the blade.

[0017] Furthermore, when calculating the lift coefficient after the blade dynamically stalls, the dynamic stall model can be used to correct the lift coefficient.

[0018] Furthermore, an unsteady aerodynamic load calculation equation is established according to the inflow velocity and the lift coefficient of the blade after dynamic stall, including: using the inflow velocity and the lift coefficient of the blade after dynamic stall, based on the blade element momentum theory, introducing the Prandtl factor to correct the tip loss, using the Prandtl method to correct the tangential force coefficient, and establishing the unsteady aerodynamic load calculation equation.

[0019] Furthermore, an aeroelastic coupling model of a pre-bent blade is constructed according to the unsteady aerodynamic load calculation equation, including: solving the unsteady aerodynamic load calculation equation using the Newton iteration method, rewriting the dynamic equation into a differential form using the implicit midpoint method, and establishing the aeroelastic coupling model of a pre-bent blade.

[0020] In a second aspect, an aeroelastic coupling model of a wind turbine blade taking into account a pre-bent shape is provided, which is constructed using the aeroelastic coupling modeling method of a wind turbine blade taking into account a pre-bent shape described in the first aspect.

[0021] On the third aspect, a method for analyzing the influence of different pre-bending parameters on the aeroelastic characteristics of wind turbine blades is provided. The aeroelastic coupling model of wind turbine blades taking into account the pre-bending shape described in the second aspect is used to analyze the influence of different pre-bending parameters on the aeroelastic characteristics of wind turbine blades.

[0022] Furthermore, the pre-bending parameters include the pre-bending starting position, the maximum pre-bending amount of the blade tip, and the bending coefficient; the influence of the aeroelastic characteristics of the blade includes:

[0023] As the initial pre-bending position moves away from the blade root, the tip flapping and shimmying deformation increases, the torsional deformation decreases, the tangential aerodynamic force changes less, and the normal aerodynamic force increases.

[0024] As the maximum prebending amount of the blade tip increases, the flapping and shimmying deformation of the blade tip increases, the torsional deformation decreases, and the normal aerodynamic load increases;

[0025] As the bending coefficient increases, the tip deformation fluctuation increases and the normal aerodynamic load increases.

[0026] It can be seen from the above technical solution that the beneficial technical effects of the present invention are as follows:

[0027] 1. Establish an accurate finite element dynamic model of the geometric beam structure of the pre-bent blade, use a small number of units to characterize the nonlinear deformation behavior of the blade, ensure the accuracy of the model and improve the continuity of the model; construct a dynamic stall model and a dynamic wake model, and establish an unsteady aerodynamic load calculation model to better simulate the actual operating conditions of the blade and improve the accuracy of aerodynamic load calculation. Use the Newton iteration method to solve the dynamic equations, obtain the velocity and stress distribution of the blade, and establish an aeroelastic coupling model of the pre-bent blade, which reduces the calculation cost.

[0028] 2. The influence of pre-bending parameters on aeroelastic characteristics was analyzed, and the correlation between the pre-bending shape of wind turbine blades and aeroelastic response was clarified, providing a theoretical basis for the pre-bending design of wind turbine blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0030] Figure 1 A schematic diagram of geometrically accurate beam cross-section deformation according to an embodiment of the present invention;

[0031] FIG2( a ) is a schematic diagram of a flow field of a wind turbine generator system according to an embodiment of the present invention;

[0032] FIG2( b ) is a diagram showing the definition of airfoil parameters of a blade cross section according to an embodiment of the present invention;

[0033] FIG3( a ) is a schematic diagram showing the radial distribution of the blade tip loss factor F according to an embodiment of the present invention;

[0034] FIG3( b ) is a schematic diagram of thrust coefficient correction when F=1 according to an embodiment of the present invention;

[0035] FIG4( a ) is a diagram showing the flapping deformation of the blade tip at different initial pre-bending positions according to an embodiment of the present invention;

[0036] FIG4( b ) is a diagram showing the tip vibration deformation at different initial pre-bending positions according to an embodiment of the present invention;

[0037] FIG5( a ) is a blade tip flapping deformation diagram of different blade tip maximum pre-bending amounts according to an embodiment of the present invention;

[0038] FIG5( b ) is a diagram showing the tip swing deformation of blades with different maximum tip pre-bending amounts according to an embodiment of the present invention;

[0039] FIG6( a ) is a diagram showing the tip flapping deformation of blades with different bending coefficients according to an embodiment of the present invention;

[0040] FIG6( b ) is a diagram showing the tip swing deformation of blades with different bending coefficients according to an embodiment of the present invention;

[0041] FIG. 7( a ) is a diagram of aerodynamic loads at different initial pre-bending positions according to an embodiment of the present invention;

[0042] FIG7( b ) is an aerodynamic load diagram of different maximum tip pre-bending amounts of an embodiment of the present invention;

[0043] FIG. 7( c ) is a diagram of aerodynamic loads for different bending coefficients according to an embodiment of the present invention;

[0044] Figure 8 It is a schematic flow chart of the aeroelastic coupling modeling method for wind turbine blades according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0046] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0047] Example

[0048] As the power of wind turbines increases, the length of blades also increases. The traditional linear beam theory can no longer accurately describe its deformation law. Although the three-dimensional finite element model is highly accurate and can obtain the complete stress distribution law, its computational efficiency is too low and it is not suitable for long-term dynamic simulation analysis. The nonlinear beam theory can use a small number of units to describe the nonlinear deformation behavior of blades, while ensuring accuracy and taking into account the computational cost, and the constructed model has good continuity.

[0049] In combination with the above research results, this embodiment provides an aeroelastic coupling modeling method for a wind turbine blade taking into account a pre-bent shape, comprising the following steps:

[0050] Step 1, establish and solve the finite element dynamic equation of the geometrically accurate beam structure of the pre-bent blade to obtain the cross-sectional velocity of the blade;

[0051] In this step, the finite element dynamic equations of the geometrically accurate beam structure of the pre-bent blade are established, including:

[0052] Calculate the mass matrix, stiffness matrix and energy matrix of each unit of the blade and assemble them according to the number of degrees of freedom to obtain the overall mass matrix, overall stiffness matrix and overall energy matrix of the blade

[0053] The finite element dynamic equation of the geometrically accurate beam structure of the pre-bent blade is established according to the blade's overall mass matrix, overall stiffness matrix, overall energy matrix and external load matrix;

[0054] The finite element dynamic equations are solved to obtain the cross-sectional velocity of the blade.

[0055] In a specific embodiment, Figure 1 is a schematic diagram of geometrically accurate beam section deformation. Figure 1 The coordinate relationship of the blade section before and after deformation described in , the blade velocity is obtained as follows:

[0056] The unit mass matrix is ​​Me:

[0057]

[0058] In the above formula, A(x) is the mechanical characteristic parameter matrix of the beam element, which is related to the unit linear mass u, polar moment of inertia J, moment of inertia I y and I z , tensile stiffness EA, shear stiffness GA, torsional stiffness GJ, bending stiffness EI y and EI z Related; N is the Lagrangian shape function matrix of the unit.

[0059] Element stiffness matrix K:

[0060]

[0061] In the above formula, B(x) is the coefficient matrix, C(x) is the material property matrix, and N is the Lagrangian shape function matrix of the element.

[0062] Unit energy matrix Ge:

[0063]

[0064] In the above formula, Q is the intermediate variable matrix, A(x) is the beam unit mechanical characteristic parameter matrix, Q(x,Ny)A(x) represents the unit momentum-strain matrix; N is the Lagrangian shape function matrix of the unit.

[0065] In this embodiment, for the unit with unit mass matrix Me, unit stiffness matrix K and unit energy matrix Ge, a quadratic unit is selected. The quadratic unit has 3 nodes, each of which has 12 degrees of freedom. Therefore, the number of degrees of freedom of the complete unit generalized mass matrix is ​​36, and the unit generalized mass matrix is ​​assembled according to the node number to obtain the blade overall mass matrix M; the assembly of the blade overall stiffness matrix K and the overall energy matrix G is similar, and will not be repeated.

[0066] The finite element dynamic equations of the geometrically accurate beam structure of the pre-bent blade are as follows:

[0067]

[0068] In the above formula, M is the overall mass matrix of the blade; K is the overall stiffness matrix of the blade; G(y(t)) is the overall energy matrix of the blade, which is a nonlinear term; f is the external load matrix; the quantity to be solved is y(t), y(t) = [F B M B V B Ω B ] T , the four vectors contained in y(t) are the blade internal forces F B 、Blade internal moment M B , blade section centerline velocity V B and the blade cross-sectional angular velocity Ω B .

[0069] Solve the finite element dynamic equations of the geometrically accurate beam structure of the pre-bent blade and obtain the blade section velocity:

[0070] Blade cross-sectional velocity V blade :

[0071]

[0072] In the above formula, V B is the velocity of the centerline of the blade section, is the blade section angular velocity vector, ξ B is the blade cross-section displacement vector.

[0073] Step 2: Calculate the inflow velocity based on the blade cross-sectional velocity

[0074] In a specific implementation, based on the cross-sectional velocity of the blade, a dynamic wake model and a dynamic stall model are established in the following manner:

[0075] First, the inflow velocity V is calculated based on the blade cross-sectional velocity rel :

[0076] V rel =v0+V blade +W

[0077] In the above formula, v0 is the local velocity of the free stream; V blade is the cross-sectional velocity of the blade, and W is the induced velocity of the blade.

[0078] In some embodiments, in order to correct the induced velocity W of the blade and obtain the final output dynamic induced velocity, a dynamic wake model is introduced:

[0079] A filter is set for the blade induced velocity W to establish a dynamic wake model, which consists of the following two first-order differential equations:

[0080]

[0081] In the above formula, W is the induced velocity of the blade, W qs is the quasi-static induced velocity; W Z is the dynamic induced speed of the final output after filtering, W Z is the term to be solved in the dynamic wake model; τ1 and τ2 are time constants, and k is a proportional constant. In the two first-order differential equations, the first equation has a solution quantity W; after W is obtained, it is substituted into the second equation, and W is obtained by filtering W. Z .

[0082] Step 3: Calculate the lift coefficient of the blade after dynamic stall

[0083] The lift coefficient after the blade dynamic stall can characterize the lift force on the blade after the dynamic stall. In some embodiments, in order to correct the lift coefficient, a dynamic stall model is introduced:

[0084] A dynamic stall model is constructed for lift, and a separation function is proposed using the dynamic wake model to simulate the lift coefficient after the blade dynamic stall is introduced; the constructed dynamic stall model and lift coefficient C L The calculation formula is:

[0085] C L = f s C l,inv (α)+(1-f s )C l,fs (α)

[0086] In the above formula, f s Indicates the degree of stall, C l,inv is the fully viscous lift coefficient; C l,fs is the lift coefficient of complete separation; α is the angle of attack.

[0087] Step 4: Establish the unsteady aerodynamic load calculation equation based on the inflow velocity and the lift coefficient after the blade dynamic stall

[0088] In this step, the inflow velocity obtained in step 2 and the lift coefficient after the blade dynamic stall obtained in step 3 are used. Based on the blade element momentum theory, the Prandtl factor is introduced to correct the tip loss, and the Prandtl method is used to correct the tangential force coefficient, and the unsteady aerodynamic load calculation equation is established.

[0089] Figure 2(a) is a schematic diagram of the flow field of a wind turbine, and Figure 2(b) is a definition diagram of the airfoil parameters of the blade section. The calculation equation for the unsteady aerodynamic load is established as follows:

[0090] The normal force F acting on the blade element with a length of dr and located at the radial position r is N , tangential force F T And the pitching moment M is:

[0091]

[0092] In the above formula, F N F is the normal force on a blade element at radial position r with a length of dr. T is the tangential force on the blade element at the radial position r and with a length of dr, E is the pitch moment; ρ is the air density, V rel is the inflow velocity, c is the chord length at the blade radial position r; C L is the lift coefficient, C D is the drag coefficient, C E is the pitching moment coefficient.

[0093] According to the blade element theory, the thrust dT and torque dM on the ring of the wind wheel plane dr can be expressed as:

[0094]

[0095] In the above formula, n is the number of blades, ρ is the air density; V rel is the inflow velocity, c is the chord length at the blade radial position r; C N is the normal force coefficient of the blade element, C T is the tangential force coefficient at the blade element, is the inflow angle.

[0096] FIG3( a ) is a schematic diagram of the radial distribution of the blade tip loss factor F according to an embodiment of the present invention, wherein the Prandtl blade tip loss factor is used to correct the assumption of an infinite number of blades:

[0097]

[0098] In the above formula, B is the number of blades; R is the tip rotation radius; r is the radial position of the blade; is the inflow angle.

[0099] Figure 3(b) is a schematic diagram of the thrust coefficient correction when F = 1. When the axial induction factor is large, the empirical relationship between the thrust coefficient and the axial induction factor is used to correct the tangential force coefficient C. T :

[0100]

[0101] In the above formula, F is the Prandtl tip loss factor; a is the axial induction factor.

[0102] Step 5: Establish the aeroelastic coupling model of the pre-bent blade

[0103] In this step, the unsteady aerodynamic load calculation equation obtained in step 3 is solved by Newton iteration method, and the dynamic equation is rewritten into differential form by implicit midpoint method to establish the aeroelastic coupling model of pre-bent blades. The expression of the model is as follows:

[0104]

[0105] In the above formula, [y] k+1 is the variable value at time step k+1, [y] k is the variable value of the previous time step k, Δt is the time step interval, f is the external load matrix, M is the blade mass matrix, K is the blade stiffness matrix, and G is the blade energy matrix.

[0106] In some embodiments, the Jacobian matrix of the aeroelastic coupling model of the pre-bent blade is solved to obtain:

[0107]

[0108] In the above formula, M is the mass matrix, K is the stiffness matrix, Δt is the time step interval, The operator satisfies the equation, This is done due to the properties of antisymmetric matrices. The solved Jacobian matrix can be used to update the estimate of the solution to the system of equations during the Newton iteration process.

[0109] The predicted value at the next moment It can be expressed as:

[0110]

[0111] Solve the predicted value for the next moment This allows the predicted value to continuously approach the true solution of the equation during the iteration process.

[0112] The wind turbine blade aeroelastic coupling modeling method provided in this embodiment takes into account the pre-bent shape, establishes an accurate finite element dynamic model of the pre-bent blade geometric beam structure, uses a small number of units to characterize the nonlinear deformation behavior of the blade, ensures the accuracy of the model and improves the continuity of the model; constructs a dynamic stall model and a dynamic wake model, and establishes an unsteady aerodynamic load calculation model to better simulate the actual operating conditions of the blade and improve the accuracy of aerodynamic load calculation. The Newton iteration method is used to solve the dynamic equations, obtain the velocity and stress distribution of the blade, and establish an aeroelastic coupling model of the pre-bent blade, which reduces the calculation cost.

[0113] In practical engineering applications, it is necessary to analyze the influence of pre-bending parameters on the aeroelastic characteristics of wind turbines. The aeroelastic coupling model of wind turbine blades taking into account the pre-bending shape described above can be used to construct an aeroelastic coupling model of wind turbine blades taking into account the pre-bending shape, which is used to analyze the influence of the aeroelastic characteristics of wind turbines. The influence of the aeroelastic characteristics of wind turbines includes:

[0114] As shown in Figures 4 to 7, as the initial pre-bending position moves away from the blade root, the flapping and swing deformation of the blade tip increases, the torsional deformation decreases, the tangential aerodynamic force changes little, and the normal aerodynamic force increases; as the maximum pre-bending amount of the blade tip increases, the flapping and swing deformation of the blade tip increases, the torsional deformation decreases, and the normal aerodynamic load increases; as the bending coefficient increases, the deformation fluctuation of the blade tip increases, and the normal aerodynamic load increases.

[0115] This embodiment analyzes the influence of pre-bending parameters on aeroelastic characteristics, clarifies the correlation between the pre-bending shape of wind turbine blades and aeroelastic response, and provides a theoretical basis for the pre-bending design of wind turbine blades.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A wind turbine blade aeroelastic coupling modeling method taking into account the pre-bent shape, characterized in that: The following steps are involved: The finite element dynamic equations of the geometrically accurate beam structure of the pre-bent blade are established and solved to obtain the cross-sectional velocity of the blade; Calculate the inflow velocity based on the blade's cross-sectional velocity; Calculate the lift coefficient of the blade after dynamic stall; The unsteady aerodynamic load calculation equation is established based on the inflow velocity and the lift coefficient of the blade after dynamic stall. The aeroelastic coupling model of pre-bent blades is constructed based on the unsteady aerodynamic load calculation equation.

2. The aeroelastic coupling modeling method for wind turbine blades taking into account the pre-bent shape according to claim 1 is characterized in that: Establish the finite element dynamic equations of the geometrically accurate beam structure of the pre-bent blade, including: Calculate the mass matrix, stiffness matrix and energy matrix of each unit of the blade and assemble them according to the number of degrees of freedom to obtain the overall mass matrix, overall stiffness matrix and overall energy matrix of the blade; The finite element dynamic equations of the geometrically precise beam structure of the pre-bent blade are established based on the blade's overall mass matrix, overall stiffness matrix, overall energy matrix and external load matrix.

3. The aeroelastic coupling modeling method for wind turbine blades taking into account the pre-bent shape according to claim 1 is characterized in that: The inflow velocity is calculated based on the cross-sectional velocity of the blade, which is equal to the sum of the local velocity of the free stream, the cross-sectional velocity of the blade, and the induced velocity of the blade.

4. The aeroelastic coupling modeling method for wind turbine blades taking into account the pre-bent shape according to claim 3 is characterized in that: When calculating the inflow velocity, the dynamic wake model can be used to correct the induced velocity of the blade.

5. The aeroelastic coupling modeling method for wind turbine blades taking into account the pre-bent shape according to claim 1 is characterized in that: When calculating the lift coefficient of the blade after dynamic stall, the dynamic stall model can be used to correct the lift coefficient.

6. The aeroelastic coupling modeling method for wind turbine blades taking into account the pre-bent shape according to claim 1 is characterized in that: The unsteady aerodynamic load calculation equation is established according to the inflow velocity and the lift coefficient of the blade after dynamic stall, including: using the inflow velocity and the lift coefficient of the blade after dynamic stall, based on the blade element momentum theory, introducing the Prandtl factor to correct the tip loss, using the Prandtl method to correct the tangential force coefficient, and establishing the unsteady aerodynamic load calculation equation.

7. The aeroelastic coupling modeling method for wind turbine blades taking into account the pre-bent shape according to claim 1 is characterized in that: The aeroelastic coupling model of the pre-bent blade is constructed according to the unsteady aerodynamic load calculation equation, including: solving the unsteady aerodynamic load calculation equation by Newton iteration method, rewriting the dynamic equation into differential form by implicit midpoint method, and establishing the aeroelastic coupling model of the pre-bent blade.

8. An aeroelastic coupling model of wind turbine blades taking into account the pre-bent shape, characterized in that: The wind turbine blade is constructed using the aeroelastic coupling modeling method taking into account the pre-bent shape as described in any one of claims 1 to 7.

9. An analysis method for the influence of different pre-bending parameters on the aeroelastic characteristics of wind turbine blades, characterized in that: Using the aeroelastic coupling model of wind turbine blades taking into account the pre-bending shape as described in claim 8, the influence of the pre-bending blades of the wind turbine on the aeroelastic characteristics of the blades under different pre-bending parameters is analyzed.

10. The method for analyzing the influence of different pre-bending parameters on the aeroelastic characteristics of wind turbine blades according to claim 9, characterized in that: The pre-bending parameters include the pre-bending starting position, the maximum pre-bending amount of the blade tip, and the bending coefficient; The influence of the blade aeroelastic characteristics includes: As the initial pre-bending position moves away from the blade root, the flapping and shimmying deformation of the blade tip increases, the torsional deformation decreases, the tangential aerodynamic force changes less, and the normal aerodynamic force increases; As the maximum prebending amount of the blade tip increases, the flapping and shimmying deformation of the blade tip increases, the torsional deformation decreases, and the normal aerodynamic load increases; As the bending coefficient increases, the tip deformation fluctuation increases and the normal aerodynamic load increases.

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