A wind turbine aeroelastic instability determination method, system, device and storage medium

Abstract

The application discloses a wind turbine aeroelastic instability discrimination method, system, equipment and storage medium, which is used for discriminating the aeroelastic instability state of the wind turbine. The wind wheel of the wind turbine is equivalent to a rigid structure fixed at the top end of the tower, the tower of the wind turbine is equivalent to a single-degree-of-freedom cantilever beam, the aeroelastic damping ratio of the whole wind turbine is obtained by combining the dynamic equation and the work done by the aerodynamic damping of each blade of the wind turbine, and then the aeroelastic instability state of the wind turbine is discriminated. The application does not need a physical experimental site, avoids complex calculation, improves the efficiency of the wind turbine aeroelastic instability discrimination, and reduces the corresponding calculation resource cost.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to a method, system, device and storage medium for determining aeroelastic instability of a wind turbine. Background Technology

[0002] The aeroelastic stability of a wind turbine (hereinafter referred to as wind turbine) refers to the vibration of the entire wind turbine system caused by the interaction between the blades, tower and rotor when the wind speed changes. It is one of the main factors affecting the working efficiency and life of the wind turbine.

[0003] With the continuous development of wind energy utilization, wind turbines are becoming increasingly larger, and the resulting aeroelastic stability issues are becoming more prominent. When a wind turbine experiences aeroelastic instability, it may experience severe vibrations or other instabilities, leading to structural damage.

[0004] Currently, there are two methods for determining the aeroelastic instability of a wind turbine: wind tunnel testing and modeling simulation. Wind tunnel testing requires a large experimental site, which results in high manufacturing costs. As wind turbines become larger, modeling simulation becomes increasingly complex, leading to a significant increase in simulation time and higher computational resource costs. Summary of the Invention

[0005] This invention provides a method, system, device, and storage medium for identifying aeroelastic instability in wind turbines, which solves the technical problem of high cost in existing methods for identifying aeroelastic instability in wind turbines.

[0006] The first aspect of this invention provides a method for determining aeroelastic instability in a wind turbine, the wind turbine comprising a tower and a rotor, the method comprising:

[0007] Obtain the tower parameters, rotor parameters, and airflow parameters of the wind turbine;

[0008] The wind turbine is equivalent to a rigid structure fixed to the top of the tower, and the tower is equivalent to a cantilever beam. Based on the deflection curve equation of the cantilever beam, the equivalent mass and equivalent stiffness of the wind turbine are calculated using the tower parameters and the wind turbine parameters.

[0009] Calculate the structural frequency of the entire wind turbine based on the equivalent mass and the equivalent stiffness.

[0010] The wind turbine is simplified as a single-degree-of-freedom mass-spring system. Combining dynamic formulas, the wind turbine parameters, airflow parameters, tower parameters, equivalent mass, and structural frequency are used to calculate the aeroelastic damping ratio of the entire wind turbine.

[0011] If the aeroelastic damping ratio is within a preset damping ratio range, the wind turbine is determined to be in an aeroelastic instability state.

[0012] Optionally, the step of equating the wind turbine to a rigid structure fixed to the top of the tower, and equating the tower to a cantilever beam, and calculating the equivalent mass and equivalent stiffness of the entire wind turbine using the tower parameters and wind turbine parameters based on the deflection curve equation of the cantilever beam, includes:

[0013] The wind turbine is equivalent to a rigid structure fixed to the top of the tower, and the tower is equivalent to a cantilever beam. Based on the deflection curve equation of the cantilever beam and using the tower parameters, the deformation displacement equation of the tower under end-face load is generated.

[0014] Using the aforementioned deformation-displacement equation, and taking the deformation of the tower under unit load as the mode of the structure, the deflection-displacement expression of the tower is generated.

[0015] Considering the deformation and displacement of the tower at different times and at different cross sections, and combining the deflection displacement expression, the displacement expression and velocity expression of the tower are generated;

[0016] Calculate the equivalent stiffness of the entire wind turbine according to the deformation displacement equation and the displacement expression;

[0017] Based on the amplitude function and the kinetic energy theorem, and combined with the velocity expression, the kinetic energy of the wind turbine tower and the kinetic energy of the wind turbine are calculated respectively. The kinetic energy of the tower and the kinetic energy of the wind turbine are added together to obtain the overall kinetic energy expression of the wind turbine.

[0018] The kinetic energy expression of the wind turbine is eliminated according to the kinetic energy theorem, and the equivalent mass of the wind turbine is calculated using the tower parameters and the rotor parameters.

[0019] Optionally, the formula for calculating the equivalent mass is:

[0020]

[0021] In the formula, M e For the equivalent mass, ρ A Let be the material density of the tower, x be the coordinate position of the cross-section of the tower, A be the cross-sectional area of ​​the tower, L be the height of the tower, E be the elastic modulus of the tower, I be the moment of inertia of the tower, and M be the total mass of the wind turbine.

[0022] Optionally, the formula for calculating the structural frequency is:

[0023]

[0024] In the formula, ωe K is the frequency of the structure. e For the equivalent stiffness, M e The equivalent mass is described above.

[0025] Optionally, simplifying the wind turbine into a single-degree-of-freedom mass-spring system, and calculating the aeroelastic damping ratio of the entire wind turbine using the wind turbine parameters, airflow parameters, tower parameters, equivalent mass, and structural frequency, in conjunction with dynamic formulas, includes:

[0026] Based on the blade element momentum theory, using the wind turbine parameters and airflow parameters, an expression for the axial aerodynamic load on each blade element of the wind turbine is generated.

[0027] The axial aerodynamic load expression is differentiated, and combined with the structural form of the dynamic formula, the aerodynamic damping expression per unit length on the blade is generated.

[0028] The aerodynamic damping expression per unit length is integrated, and the aerodynamic damping of the wind turbine is calculated using the tower parameters;

[0029] The aeroelastic damping ratio of the entire wind turbine is calculated using the aerodynamic damping, the equivalent mass, and the structural frequency.

[0030] Optionally, the formula for calculating the aerodynamic damping is:

[0031]

[0032] In the formula, C a Where is the aerodynamic damping of the wind turbine, B is the number of blades on the wind turbine, ρ is the air density, Ω is the angular velocity of the wind turbine, L is the height of the tower, E is the elastic modulus of the tower, I is the moment of inertia of the tower, c is the airfoil chord length of the blade, and C' is the airfoil chord length of the wind turbine. L R is the slope of the lift coefficient of the blade, r is the coordinate position of the cross-section of the blade, and R is the length of the blade.

[0033] Optionally, the formula for calculating the aeroelastic damping ratio is:

[0034]

[0035] In the formula, ξ is the aeroelastic damping ratio, B is the number of blades on the wind turbine, ρ is the air density, Ω is the angular velocity of the wind turbine, L is the height of the tower, and M... e For the equivalent mass, ω e Let E be the structural frequency, E be the elastic modulus of the tower, I be the moment of inertia of the tower, c be the airfoil chord length of the blade, and C' be the moment of inertia of the tower. LR is the slope of the lift coefficient of the blade, r is the coordinate position of the cross-section of the blade, and R is the length of the blade.

[0036] A second aspect of the present invention provides a wind turbine aeroelastic instability detection system, the wind turbine including a tower and a rotor, the system comprising:

[0037] The data acquisition module is used to acquire the tower parameters, rotor parameters, and airflow parameters of the wind turbine.

[0038] The equivalent calculation module is used to treat the wind turbine as a rigid structure fixed to the top of the tower and the tower as a cantilever beam. Based on the deflection curve equation of the cantilever beam, the equivalent mass and equivalent stiffness of the wind turbine are calculated using the tower parameters and the wind turbine parameters.

[0039] The structural frequency calculation module is used to calculate the structural frequency of the entire wind turbine based on the equivalent mass and the equivalent stiffness.

[0040] The aeroelastic damping ratio calculation module is used to simplify the wind turbine into a single-degree-of-freedom mass-spring system, and calculate the aeroelastic damping ratio of the entire wind turbine by combining the dynamic formula, the wind turbine parameters, the airflow parameters, the tower parameters, the equivalent mass and the structural frequency.

[0041] The instability detection module is used to determine that the wind turbine is in an aeroelastic instability state if the aeroelastic damping ratio is within a preset damping ratio range.

[0042] A third aspect of the present invention provides a wind turbine aeroelastic instability detection device, comprising:

[0043] Memory, used to store computer programs;

[0044] A processor for executing the computer program to implement the steps of the wind turbine aeroelastic instability detection method as described in any of the preceding claims.

[0045] A fourth aspect of the present invention provides a computer-readable storage medium storing instructions that, when executed on a terminal device, cause the terminal device to perform the wind turbine aeroelastic instability detection method as described in any of the preceding claims.

[0046] As can be seen from the above technical solutions, the present invention has the following advantages:

[0047] This invention treats the wind turbine rotor as a rigid structure fixed to the top of the tower, and the tower as a single-degree-of-freedom cantilever beam. By combining dynamic equations and the work done by the aerodynamic damping of each blade, the aeroelastic damping ratio of the entire wind turbine is calculated, thereby determining the aeroelastic instability state of the wind turbine. This invention does not require a physical experimental site and avoids complex calculations, improving the efficiency of wind turbine aeroelastic instability determination and reducing the corresponding computational resource costs. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a flowchart illustrating the steps of a wind turbine aeroelastic instability detection method provided in Embodiment 1 of the present invention.

[0050] Figure 2 This is a simplified structural diagram of a wind turbine provided in Embodiment 1 of the present invention;

[0051] Figure 3 This is a simplified diagram of a one-dimensional cantilever beam structure provided in Embodiment 1 of the present invention;

[0052] Figure 4 This is a schematic diagram of the force distribution on a wind turbine blade provided in Embodiment 1 of the present invention;

[0053] Figure 5 This is a structural block diagram of a wind turbine aeroelastic instability discrimination system provided in Embodiment 2 of the present invention. Detailed Implementation

[0054] This invention provides a method, system, device, and storage medium for identifying aeroelastic instability in wind turbines, which addresses the technical problem of high cost in existing methods for identifying aeroelastic instability in wind turbines.

[0055] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0056] Please see Figure 1 , Figure 1The flowchart illustrates the steps of a wind turbine aeroelastic instability detection method provided in Embodiment 1 of the present invention.

[0057] Embodiment 1 of the present invention provides a method for determining aeroelastic instability of a wind turbine, characterized in that the wind turbine includes a tower and a rotor, and the method for determining aeroelastic instability of the wind turbine includes:

[0058] Step 101: Obtain the tower parameters, rotor parameters, and airflow parameters of the wind turbine.

[0059] It should be noted that, as Figure 2 As shown, the structure of a wind turbine can be simplified to include a tower and a rotor, facilitating subsequent analysis of the stress and vibration of different structural components. Tower parameters include dimensional, material, and performance parameters such as the tower's elastic modulus, moment of inertia, length, cross-sectional area, and material density. The rotor has multiple blades, and rotor parameters include dimensional and performance parameters such as the rotor's total mass, number of blades, blade length, lift coefficient, airfoil chord length, and rotor angular velocity.

[0060] Step 102: Treat the wind turbine as a rigid structure fixed to the top of the tower, and the tower as a cantilever beam. Based on the deflection curve equation of the cantilever beam, calculate the equivalent mass and equivalent stiffness of the wind turbine using tower parameters and wind turbine parameters.

[0061] See also Figure 3 , Figure 3 This is a simplified structural diagram of a one-dimensional cantilever beam. It can be understood that by simplifying the entire wind turbine structure to include the tower and rotor, and given the tower's large aspect ratio and its fixed base, the rotor can be equated to a rigid structure fixed to the top of the tower, and the tower itself can be equated to a cantilever beam. This allows for the analysis of the wind turbine's motion under end-face loads.

[0062] In a preferred embodiment, step 102 specifically includes the following sub-steps S11 to S16:

[0063] S11. Treat the wind turbine as a rigid structure fixed to the top of the tower, and the tower as a cantilever beam. Based on the deflection curve equation of the cantilever beam, and using the tower parameters, generate the deformation and displacement equation of the tower under end-face load.

[0064] The deformation and displacement equation of the tower under end-face load is:

[0065]

[0066] In the formula, P is the end face load on the tower, u(x) is the deformation displacement of the cross section x of the tower under the action of the end face load P, x is the coordinate position of the cross section of the tower, L is the height of the tower, E is the elastic modulus of the tower, and I is the moment of inertia of the tower.

[0067] It is understandable that deflection is the linear displacement of the centroid of the cross-section along a direction perpendicular to the axis during bending deformation. The value of the deflection of a cantilever beam during bending deformation varies with the position of the cross-section. When discussing bending deformation problems, the x-axis is usually chosen to be positive to the right, and the y-axis is chosen to be positive downwards. A deflection curve equation is established with the independent variable being the coordinate x of the cross-section position of the cantilever beam and the dependent variable being the deflection at the x-section. In this invention, since the tower is vertically fixed to the ground, the direction from the bottom of the tower to the top is chosen as the positive direction of the x-axis.

[0068] S12. Using the deformation displacement equation, the deformation of the tower under unit load is taken as the mode of the structure to generate the deflection displacement expression of the tower.

[0069] Assuming the deformation under a unit load is taken as the mode of the structure, the deflection displacement of the tower can be expressed as:

[0070]

[0071] In the formula, φ(x) is the deflection displacement of the cross section x of the tower.

[0072] The unit load, i.e., the end face load P=1, is used in this sub-step. The unit load method is employed. To calculate the displacement of any section of the beam in any direction, a unit load can be applied to that section along the direction of the displacement to be determined, and then the displacement can be calculated.

[0073] S13. Considering the deformation and displacement of the tower at different times and across different cross sections, and combining the deflection displacement expression, generate the displacement expression and velocity expression for the tower.

[0074] It should be noted that rewriting the deformation displacement equation as a function of x and t yields the expressions for displacement, velocity, and acceleration as follows:

[0075]

[0076]

[0077]

[0078] In the formula, t is the time during which the tower is subjected to the end face load, u(x,t) represents the displacement of the tower cross section x at time t, and α(t) is the proportion of the deflection displacement φ(x) at time t. This represents the velocity of the tower's cross-section x at time t. This represents the acceleration of the tower cross section x at time t;

[0079] From the above formula, the displacement of the top of the tower can be obtained as:

[0080]

[0081] In the formula, u(L,t) represents the displacement of the end face of the tower at time t.

[0082] S14. Calculate the equivalent stiffness of the entire wind turbine according to the deformation displacement equation and displacement expression.

[0083] Since the end face load P is:

[0084]

[0085] In the formula, K e The equivalent stiffness of the wind turbine;

[0086] but:

[0087]

[0088] The equivalent stiffness K can be obtained. e =1.

[0089] S15. Based on the amplitude function and the kinetic energy theorem, and combined with the velocity expression, calculate the tower kinetic energy and the rotor kinetic energy of the wind turbine respectively. Add the tower kinetic energy and the rotor kinetic energy to obtain the overall kinetic energy expression of the wind turbine.

[0090] The kinetic energy of the wind turbine tower, calculated using the amplitude function, is added to the kinetic energy of the wind turbine rotor, calculated using the work-energy theorem, to obtain the expression for the total kinetic energy of the wind turbine:

[0091]

[0092] In the formula, T is the kinetic energy of the entire wind turbine, and ρ A Let ρ be the material density of the tower, A be the cross-sectional area of ​​the tower's cross section x, φ(L) be the deflection displacement at the top of the tower, and M be the total mass of the wind turbine.

[0093] S16. Eliminate variables from the kinetic energy expression of the wind turbine according to the kinetic energy theorem, and calculate the equivalent mass of the wind turbine using tower parameters and rotor parameters.

[0094] More preferably, according to the kinetic energy theorem Eliminating variables from the overall kinetic energy expression of the wind turbine, we obtain the equivalent mass of the entire wind turbine as follows:

[0095]

[0096] In the formula, Me The equivalent mass of the entire wind turbine.

[0097] Step 103: Calculate the structural frequency of the wind turbine based on the equivalent mass and equivalent stiffness of the entire wind turbine.

[0098] In a preferred embodiment, the formula for calculating the structural frequency of the wind turbine is:

[0099]

[0100] In the formula, ω e M is the structural frequency. e K represents the equivalent mass of the entire wind turbine. e This represents the equivalent stiffness of the wind turbine.

[0101] Step 104: Simplify the wind turbine into a single-degree-of-freedom mass-spring system. Using dynamic formulas, wind turbine parameters, airflow parameters, tower parameters, equivalent mass, and structural frequency, calculate the aeroelastic damping ratio of the entire wind turbine.

[0102] In a preferred embodiment, step 104 specifically includes the following sub-steps S21 to S24:

[0103] S21. Based on the blade element momentum theory, using wind turbine parameters and airflow parameters, generate the axial aerodynamic load expression for each blade element on the wind turbine blade.

[0104] See also Figure 4 , Figure 4 This is a schematic diagram of the force distribution on the blade. The axial aerodynamic load on each blade element of the wind turbine blade is:

[0105]

[0106] In the formula, dF X / dr is the axial aerodynamic load on the blade element, F X Let r be the force acting on the wind turbine along its axis, r be the coordinate position of the blade element, ρ be the air density, and U be the force acting on the wind turbine along its axis. r C is the net tangential velocity of the airflow. L denoted as ρ, where ρ is the lift coefficient of the blade, and c is the airfoil chord length of the blade.

[0107] S22. Differentiate the expression for axial aerodynamic load and, in conjunction with the structural form of the dynamic formula, generate the expression for aerodynamic damping per unit length on the blade.

[0108] It should be noted that when the net tangential velocity of the airflow is much greater than the axial induced velocity of the airflow, the inflow angle is:

[0109]

[0110] In the formula, Ud λ is the axial induced velocity of the airflow, and λ is the inflow angle between the relative wind and the blades;

[0111] We can obtain:

[0112]

[0113] The slope of the lift coefficient can then be written as:

[0114]

[0115] In the formula, α is the angle of attack of the blade, β is the twist angle of the blade, and C' L The slope of the lift coefficient of the blade;

[0116] Since the angle of attack equals the angle of attack plus the angle of twist, that is:

[0117]

[0118] Since the twist angle is a constant, we can obtain:

[0119]

[0120] Therefore, the change in blade aerodynamic load caused by tower vibration is as follows:

[0121]

[0122] Since the axial induced velocity of the airflow varies with wind speed and structural motion, we can obtain:

[0123]

[0124] In the formula, u is the wind speed. The axial additional velocity of the wind turbine is caused by the vibration of the wind turbine rotor due to the tower structure, which is the vibration velocity of the blades caused by the vibration of the tower structure. Therefore, the vibration velocity of the blades can be obtained from the overall deformation velocity of the tower at the top. ;

[0125] The change in blade aerodynamic load caused by tower vibration can then be obtained as follows:

[0126]

[0127] The aeroelastic characteristics caused by tower vibration can be simplified to a single-degree-of-freedom mass-spring system of the wind turbine. Therefore, the aerodynamic load generated by the vibration of this single-degree-of-freedom mass-spring system is... According to the dynamic equations of a single-degree-of-freedom mass-spring system ( Where M represents the mass matrix, K represents the stiffness matrix, and x, Let displacement and acceleration represent the displacement and acceleration respectively, and F represent the load on the single-degree-of-freedom mass-spring system. From this, we can obtain:

[0128]

[0129]

[0130] In the formula, X represents the axial structural displacement of the wind turbine caused by tower vibration. , The axial structural acceleration of the wind turbine. M is the total mass of the wind turbine, and K is the stiffness of the wind turbine;

[0131] From the dynamic equation ( Where M represents the mass matrix, C represents the damping matrix, K represents the stiffness matrix, and x, , Given the structural form of displacement, velocity, and acceleration respectively, and P representing the load matrix, the expression for aerodynamic damping per unit length on the blade can be obtained as follows:

[0132]

[0133] In the formula, dC a / dr represents the aerodynamic damping per unit length on the blade, C a This is the aerodynamic damping of the wind turbine.

[0134] S23. Perform an integral operation on the expression for aerodynamic damping per unit length, and calculate the aerodynamic damping of the wind turbine using tower parameters.

[0135] Integrating the expression for aerodynamic damping per unit length, we obtain the aerodynamic damping of the wind turbine as follows:

[0136]

[0137] In the formula, B is the number of blades on the wind turbine, Ω is the angular velocity of the wind turbine, and R is the length of the blade.

[0138] S24. Using aerodynamic damping, equivalent mass, and structural frequency, calculate the aeroelastic damping ratio of the entire wind turbine.

[0139] The aeroelastic damping ratio of the entire wind turbine can be obtained as follows:

[0140]

[0141] In the formula, ξ is the aeroelastic damping ratio, and M e For the equivalent mass of the entire wind turbine, ω e This refers to the structural frequency of the entire wind turbine.

[0142] Step 105: If the aeroelastic damping ratio is within the preset damping ratio range, the wind turbine is determined to be in an aeroelastic instability state.

[0143] It is understandable that the aeroelastic damping ratio of a wind turbine refers to the ratio between the wind turbine's ability to resist vibration when wind speed changes and the system's dynamic response. The preset damping ratio range can be set based on experience or actual application conditions, preferably set to [-∞, 0). When the aeroelastic damping ratio is less than 0, it can be determined that the wind turbine is in an aeroelastic instability state, and a significant increase in vibration will occur.

[0144] Embodiment 1 of the present invention treats the wind turbine rotor as a rigid structure fixed to the top of the tower and the wind turbine tower as a single-degree-of-freedom cantilever beam. By combining the dynamic equations and the work done by the aerodynamic damping of each blade on the wind turbine rotor, the aeroelastic damping ratio of the entire wind turbine is obtained, thereby determining the aeroelastic instability state of the wind turbine. This method does not require expensive physical test sites and avoids complex calculations, thus improving the efficiency of determining the aeroelastic instability of wind turbines and reducing the corresponding computational resource costs.

[0145] Please refer to 5. Figure 5 This is a structural block diagram of a wind turbine aeroelastic instability discrimination system provided in Embodiment 2 of the present invention.

[0146] Embodiment 2 of the present invention provides a wind turbine aeroelastic instability detection system, wherein the wind turbine includes a tower and a rotor, and the wind turbine aeroelastic instability detection system includes:

[0147] The data acquisition module 501 is used to acquire the tower parameters, rotor parameters, and airflow parameters of the wind turbine.

[0148] The equivalent calculation module 502 is used to treat the wind turbine as a rigid structure fixed to the top of the tower and the tower as a cantilever beam. Based on the deflection curve equation of the cantilever beam, the equivalent mass and equivalent stiffness of the wind turbine are calculated using tower parameters and wind turbine parameters.

[0149] The structural frequency calculation module 503 is used to calculate the structural frequency of the entire wind turbine based on the equivalent mass and equivalent stiffness.

[0150] The aeroelastic damping ratio calculation module 504 is used to simplify the wind turbine into a single-degree-of-freedom mass-spring system. Combining dynamic formulas, it uses wind turbine parameters, airflow parameters, tower parameters, equivalent mass, and structural frequency to calculate the aeroelastic damping ratio of the entire wind turbine.

[0151] The instability detection module 505 is used to determine that the wind turbine is in an aeroelastic instability state if the aeroelastic damping ratio is within a preset damping ratio range.

[0152] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the system and modules described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0153] Corresponding to the above methods and system embodiments, this invention also provides a wind turbine aeroelastic instability discrimination device and a computer-readable storage medium, which can be referred to in conjunction with the above.

[0154] An embodiment of the present invention provides a wind turbine aeroelastic instability detection device, comprising:

[0155] Memory, used to store computer programs;

[0156] A processor for executing a computer program to implement the steps of the wind turbine aeroelastic instability detection method as described in any of the preceding claims.

[0157] The present invention provides a computer-readable storage medium storing instructions that, when executed on a terminal device, cause the terminal device to perform the wind turbine aeroelastic instability determination method as described in any of the above embodiments.

[0158] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0159] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0160] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0161] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0162] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining aeroelastic instability in wind turbines, characterized in that, The wind turbine includes a tower and a rotor, and the method includes: Obtain the tower parameters, rotor parameters, and airflow parameters of the wind turbine; The wind turbine is equivalent to a rigid structure fixed to the top of the tower, and the tower is equivalent to a cantilever beam. Based on the deflection curve equation of the cantilever beam, the equivalent mass and equivalent stiffness of the wind turbine are calculated using the tower parameters and the wind turbine parameters. Calculate the structural frequency of the entire wind turbine based on the equivalent mass and the equivalent stiffness. The wind turbine is simplified as a single-degree-of-freedom mass-spring system. Combining dynamic formulas, the wind turbine parameters, airflow parameters, tower parameters, equivalent mass, and structural frequency are used to calculate the aeroelastic damping ratio of the entire wind turbine. If the aeroelastic damping ratio is within a preset damping ratio range, the wind turbine is determined to be in an aeroelastic instability state. The process of equating the wind turbine rotor to a rigid structure fixed to the top of the tower, and equating the tower to a cantilever beam, involves calculating the equivalent mass and equivalent stiffness of the entire wind turbine using the tower parameters and the wind turbine parameters, based on the deflection curve equation of the cantilever beam. The wind turbine is equivalent to a rigid structure fixed to the top of the tower, and the tower is equivalent to a cantilever beam. Based on the deflection curve equation of the cantilever beam and using the tower parameters, the deformation displacement equation of the tower under end-face load is generated. Using the aforementioned deformation-displacement equation, and taking the deformation of the tower under unit load as the mode of the structure, the deflection-displacement expression of the tower is generated. Considering the deformation and displacement of the tower at different times and at different cross sections, and combining the deflection displacement expression, the displacement expression and velocity expression of the tower are generated; Calculate the equivalent stiffness of the entire wind turbine according to the deformation displacement equation and the displacement expression; Based on the amplitude function and the kinetic energy theorem, and combined with the velocity expression, the kinetic energy of the wind turbine tower and the kinetic energy of the wind turbine are calculated respectively. The kinetic energy of the tower and the kinetic energy of the wind turbine are added together to obtain the overall kinetic energy expression of the wind turbine. The kinetic energy expression of the wind turbine is eliminated according to the kinetic energy theorem, and the equivalent mass of the wind turbine is calculated using the tower parameters and the rotor parameters. The formula for calculating the equivalent mass is: In the formula, M e For the equivalent mass, ρ A Let be the material density of the tower, x be the coordinate position of the cross-section of the tower, A be the cross-sectional area of ​​the tower, L be the height of the tower, E be the elastic modulus of the tower, I be the moment of inertia of the tower, and M be the total mass of the wind turbine.

2. The method for determining aeroelastic instability of a wind turbine according to claim 1, characterized in that, The formula for calculating the structure frequency is: In the formula, ω e K is the frequency of the structure. e For the equivalent stiffness, M e The equivalent mass is described above.

3. The method for determining aeroelastic instability of a wind turbine according to claim 1, characterized in that, The process of simplifying the wind turbine into a single-degree-of-freedom mass-spring system, and using dynamic formulas, employing the wind turbine parameters, airflow parameters, tower parameters, equivalent mass, and structural frequency, to calculate the aeroelastic damping ratio of the entire wind turbine includes: Based on the blade element momentum theory, using the wind turbine parameters and airflow parameters, an expression for the axial aerodynamic load on each blade element of the wind turbine is generated. The axial aerodynamic load expression is differentiated, and combined with the structural form of the dynamic formula, the aerodynamic damping expression per unit length on the blade is generated. The aerodynamic damping expression per unit length is integrated, and the aerodynamic damping of the wind turbine is calculated using the tower parameters; The aeroelastic damping ratio of the entire wind turbine is calculated using the aerodynamic damping of the wind turbine rotor, the equivalent mass, and the structural frequency.

4. The method for determining aeroelastic instability of a wind turbine according to claim 3, characterized in that, The formula for calculating the aerodynamic damping of the wind turbine is as follows: In the formula, C a Where is the aerodynamic damping of the wind turbine, B is the number of blades on the wind turbine, ρ is the air density, Ω is the angular velocity of the wind turbine, L is the height of the tower, E is the elastic modulus of the tower, I is the moment of inertia of the tower, c is the airfoil chord length of the blade, and C' is the airfoil chord length of the wind turbine. L R is the slope of the lift coefficient of the blade, r is the coordinate position of the cross-section of the blade, and R is the length of the blade.

5. The method for determining aeroelastic instability of a wind turbine according to claim 1, characterized in that, The formula for calculating the aeroelastic damping ratio is: In the formula, ξ is the aeroelastic damping ratio, B is the number of blades on the wind turbine, ρ is the air density, Ω is the angular velocity of the wind turbine, L is the height of the tower, and M is the air density. e For the equivalent mass, ω e Let E be the structural frequency, E be the elastic modulus of the tower, I be the moment of inertia of the tower, c be the airfoil chord length of the blade, and C' be the moment of inertia of the tower. L R is the slope of the lift coefficient of the blade, r is the coordinate position of the cross-section of the blade, and R is the length of the blade.

6. A wind turbine aeroelastic instability detection system, characterized in that, The wind turbine includes a tower and a rotor, and the system includes: The data acquisition module is used to acquire the tower parameters, rotor parameters, and airflow parameters of the wind turbine. The equivalent calculation module is used to treat the wind turbine as a rigid structure fixed to the top of the tower and the tower as a cantilever beam. Based on the deflection curve equation of the cantilever beam, the equivalent mass and equivalent stiffness of the wind turbine are calculated using the tower parameters and the wind turbine parameters. The structural frequency calculation module is used to calculate the structural frequency of the entire wind turbine based on the equivalent mass and the equivalent stiffness. The aeroelastic damping ratio calculation module is used to simplify the wind turbine into a single-degree-of-freedom mass-spring system, and calculate the aeroelastic damping ratio of the entire wind turbine by combining the dynamic formula, the wind turbine parameters, the airflow parameters, the tower parameters, the equivalent mass and the structural frequency. The instability detection module is used to determine that the wind turbine is in an aeroelastic instability state if the aeroelastic damping ratio is within a preset damping ratio range. The equivalent calculation module is specifically used for: The wind turbine is equivalent to a rigid structure fixed to the top of the tower, and the tower is equivalent to a cantilever beam. Based on the deflection curve equation of the cantilever beam and using the tower parameters, the deformation displacement equation of the tower under end-face load is generated. Using the aforementioned deformation-displacement equation, and taking the deformation of the tower under unit load as the mode of the structure, the deflection-displacement expression of the tower is generated. Considering the deformation and displacement of the tower at different times and at different cross sections, and combining the deflection displacement expression, the displacement expression and velocity expression of the tower are generated; Calculate the equivalent stiffness of the entire wind turbine according to the deformation displacement equation and the displacement expression; Based on the amplitude function and the kinetic energy theorem, and combined with the velocity expression, the kinetic energy of the wind turbine tower and the kinetic energy of the wind turbine are calculated respectively. The kinetic energy of the tower and the kinetic energy of the wind turbine are added together to obtain the overall kinetic energy expression of the wind turbine. The kinetic energy expression of the wind turbine is eliminated according to the kinetic energy theorem, and the equivalent mass of the wind turbine is calculated using the tower parameters and the rotor parameters. The formula for calculating the equivalent mass is: In the formula, M e For the equivalent mass, ρ A Let be the material density of the tower, x be the coordinate position of the cross-section of the tower, A be the cross-sectional area of ​​the tower, L be the height of the tower, E be the elastic modulus of the tower, I be the moment of inertia of the tower, and M be the total mass of the wind turbine.

7. A wind turbine aeroelastic instability detection device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the steps of the wind turbine aeroelastic instability detection method as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a terminal device, cause the terminal device to perform the wind turbine aeroelastic instability detection method as described in any one of claims 1 to 5.

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