Method and system for optimizing steering parameters of a variable-angle segment of a latticed tower minimizing prestress loss

Abstract

The application discloses a latticed tower variable-angle-section turning parameter optimization method and system minimizing prestress loss, belongs to the technical field of wind power generation latticed tower design, and comprises the following steps: a parameterized finite element model containing prestress tendon turning channel geometric characteristic parameters is established; at least one parameter is selected from the prestress tendon turning channel geometric characteristic parameters as an optimization design variable; a prestress loss calculation model is established, and the total amount of prestress loss is expressed as a function of the optimization design variable; an optimization mathematical model of the variable-angle-section turning parameter is established; the optimal design variable combination minimizing the objective function is searched within the constraint condition range; the structural performance of the turning area is verified to see whether the design requirement is met; if the verification is passed, the optimal variable-angle-section turning parameter combination is output; if the verification is not passed, the constraint condition or the optimization algorithm parameter is adjusted, and then the re-solution is returned until the verification is passed. The application can significantly reduce the prestress loss.

Description

Technical Field

[0001] This invention belongs to the field of wind power lattice tower design technology, specifically involving a method and system for optimizing the steering parameters of the variable angle section of a lattice tower to minimize prestress loss. It is particularly suitable for the structural parameter optimization design of lattice towers for ultra-high hub large-capacity long-blade wind turbines that employ prestressed steering technology. Background Technology

[0002] In recent years, as wind turbines have developed towards larger capacity, higher hubs, and longer blades, hub heights exceeding 140 meters have become commonplace. Traditional conical steel towers face severe challenges in terms of transportation, economy, and safety. Prestressed steel-concrete composite lattice towers, due to their advantages such as high material utilization, high stress efficiency, high degree of industrialized construction, and small unit size for easy disassembly and transportation, have become an important technological direction for ultra-high wind turbine towers.

[0003] A wind turbine unit employing a blade clearance adaptive prestressed steel-concrete lattice tower has recently been officially connected to the grid. Its core innovation lies in the use of prestressed steering technology, enabling the steel-concrete lattice section to extend beyond the blade tip. To achieve blade clearance self-adaptation, lattice wind turbine towers typically employ a combination configuration of "expanded foot section + variable angle section + straight section." The expanded foot section, located below the blade tip, has a cross-sectional dimension that gradually increases from top to bottom to provide sufficient anti-overturning moment. The straight section, located above the blade tip, has a cross-sectional dimension that remains constant along the height direction. The variable angle section connects the expanded foot section and the straight section, ensuring a smooth transition in the tower's cross-sectional dimensions. Within the variable angle section, the vertical prestressing tendons running through the main column need to rotate according to the changes in the tower's cross-sectional dimensions. Existing technology typically sets prestressed cable bundle channels axially within the variable angle section and forms a smooth, inwardly convex structure facing the rotating side at the cable bundle turning position, with the cable bundle channel's cross-section set as a bell-shaped hole. However, existing technology still has the following problems: (1) The selection of prestressing tendon turning parameters in variable angle segments lacks sufficient theoretical basis. At present, it mainly relies on engineering experience or repeated trial calculations to determine the parameters, which makes it difficult to ensure that the prestress loss is minimized. (2) The quantitative mapping relationship between steering parameters and prestress loss is not yet clear, and a systematic analysis model is lacking; (3) There is still a lack of prestress loss optimization design methods for specific geometric and stress boundary conditions of variable angle sections of lattice wind turbine towers; (4) The design of the steering parameters failed to achieve coordinated optimization with the overall structural performance of the tower (such as stiffness, frequency, stability, etc.), resulting in a disconnect between local design and overall requirements.

[0004] Therefore, developing a systematic design method for optimizing the steering parameters of variable-angle sections to minimize prestress loss is of great significance for improving the design level and structural performance of lattice wind turbine towers. Summary of the Invention

[0005] The present invention aims to provide a method and system for optimizing the steering parameters of the variable angle section of a lattice tower to minimize prestress loss, in order to solve the problems in the prior art such as lack of theoretical basis for the selection of steering parameters, lack of quantitative analysis model between steering parameters and prestress loss, difficulty in accurately controlling steering loss, and disconnect between steering parameter design and overall tower performance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The optimization method for steering parameters of variable-angle sections in lattice towers to minimize prestress loss includes the following steps: S1. Based on the overall design parameters of the lattice wind turbine tower, determine the geometric parameters of the variable angle section and establish a parametric finite element model that includes the geometric feature parameters of the prestressed tendon turning channel. S2. Select at least one parameter from the geometric characteristic parameters of the prestressed tendon turning channel as an optimization design variable; S3. Establish a prestress loss calculation model, and calculate the total prestress loss. The total prestress loss is expressed as a function of the optimized design variables. This includes a combination of various factors such as anchor deformation and prestressed tendon shrinkage loss, friction loss between prestressed tendons and the inner wall of the turning channel, concrete elastic compression loss, concrete shrinkage and creep loss, and prestressed tendon stress relaxation loss. S4. With the minimization of prestress loss as the objective function and structural safety and construction requirements as constraints, establish an optimization mathematical model for the turning parameters of the variable angle segment; S5. Based on the optimization mathematical model of the variable angle segment steering parameters, an intelligent optimization algorithm is used to search for the optimal combination of design variables that minimizes the objective function within the constraints. S6. Substitute the optimal design variable combination into the parameterized finite element model, perform refined finite element analysis, and verify whether the structural performance of the turning area meets the design requirements. S7. If the verification passes, output the optimal combination of steering parameters for the variable angle segment; if the verification fails, adjust the constraints or optimize the algorithm parameters and return to step S5 to solve again until the verification passes.

[0007] A further improvement of the present invention is that the geometric parameters of the variable angle segment in step S1 include: the height of the variable angle segment. , bottom cross-sectional width of the variable angle segment Width of the top section of the variable angle segment The tilt angle of the main column within the angle section and the total turning angle of the prestressing tendons within the angle-changing section. .

[0008] A further improvement of the present invention is that the geometric characteristic parameters of the prestressed tendon turning channel in step S1 include: the radius of curvature of the turning channel. The cross-sectional dimensions of the bell-shaped hole, the contour curve parameters of the smooth inner convex structure, and the length of the turning section. and the coefficient of friction of the inner wall of the steering channel At least one of them.

[0009] A further improvement of the present invention is that the cross-sectional dimensional parameters of the bell-shaped hole include: the diameter of the large end. With small end diameter ratio , And the dimensional variation law of the bell-shaped hole cross section along the height direction of the variable angle segment, the contour curve shape of the smooth inner convex structure includes circular arc curve, parabola, catenary or B-spline curve; The radius of curvature of the steering channel Variable curvature radius described by constant curvature radius, linearly varying curvature radius, piecewise constant curvature radius, or spline curve.

[0010] A further improvement of the present invention is that the prestress loss in step S3 is calculated according to the formula in standard GB / T 50010.

[0011] A further improvement of the present invention is that the constraint conditions in step S4 include at least one of the following: (1) Upper limit constraint on prestress loss: ,in, The upper limit of the allowable prestress loss is specified. (2) Lower limit constraint of turning curvature radius: ,in, The minimum allowable radius of curvature is required to ensure that the prestressed tendons do not experience excessive bending stress and local compressive stress. (3) Constraints on the cross-sectional dimensions of the bell-shaped hole: ,in, The diameter of the prestressing tendon. To meet minimum clearance requirements, The maximum permissible rate of change of cross section; (4) Bending stress constraint of prestressed tendons: ,in, This refers to the additional bending stress generated by the prestressing tendons due to their turning and bending. To allow for bending stress; (5) Contact stress constraint of the inner wall of the steering channel ,in, This refers to the contact compressive stress between the prestressed tendon and the inner wall of the turning channel. For prestressing tendon tension, The allowable compressive stress of the duct material: (6) Length constraint of turning section: ,in, Minimum length of the steering segment to ensure smooth steering transition; (7) Overall frequency constraint of the tower: ,in, The first-order natural frequency of the tower, Minimum permissible frequency to avoid the rotational frequency of the wind turbine and the passing frequency of the blades; (8) Bearing capacity constraints of main column sections.

[0012] A further improvement of this invention is that the objective function in step S4 adopts a weighted multi-objective optimization form: Where F(x) is the overall objective function value, x is the design variable vector, and C(x) is the cost function related to the manufacturing cost or construction difficulty of the steering channel. and These are the weighting coefficients.

[0013] A further improvement of the present invention is that the intelligent optimization algorithm in step S5 is one of the following: genetic algorithm, particle swarm optimization algorithm, simulated annealing algorithm, ant colony algorithm, or optimization algorithm based on surrogate model.

[0014] A further improvement of the present invention is that the verification of whether the structural performance of the turning area meets the design requirements in step S6 includes: stress distribution of prestressed tendons in the turning area, local bearing stress of concrete on the inner wall of the turning channel, overall stress and deformation of the main column of the variable angle section in the turning area, and comparison and verification of the finite element analysis results and calculation model results of the total prestress loss.

[0015] A system for optimizing the steering parameters of variable-angle sections of lattice towers to minimize prestress loss includes: Parametric finite element model establishment unit: Based on the overall design parameters of the lattice wind turbine tower, determine the geometric parameters of the variable angle section, and establish a parametric finite element model including the geometric feature parameters of the prestressed tendon turning channel; Optimization design variable selection unit: Select at least one parameter from the geometric characteristic parameters of the prestressed tendon turning channel as the optimization design variable; Prestress Loss Calculation Model Establishment Unit: Establish a prestress loss calculation model, and calculate the total prestress loss. The total prestress loss is expressed as a function of the optimized design variables. This includes a combination of various factors such as anchor deformation and prestressed tendon shrinkage loss, friction loss between prestressed tendons and the inner wall of the turning channel, concrete elastic compression loss, concrete shrinkage and creep loss, and prestressed tendon stress relaxation loss. Optimization of mathematical model building unit: Taking the minimization of prestress loss as the objective function and structural safety and construction requirements as constraints, an optimization mathematical model for the turning parameters of the variable angle segment is established; Optimal design variable combination acquisition unit: Based on the optimization mathematical model of the variable angle segment steering parameters, an intelligent optimization algorithm is used to search for the optimal design variable combination that minimizes the objective function within the constraints. Finite element analysis unit: Substitute the optimal design variable combination into the parameterized finite element model to perform refined finite element analysis and verify whether the structural performance of the turning area meets the design requirements; Judgment Unit: If the verification passes, output the optimal combination of steering parameters for the variable angle segment; if the verification fails, adjust the constraints or optimize the algorithm parameters and return to the optimal design variable combination to obtain the unit for re-solving until the verification passes.

[0016] Compared with the prior art, the present invention has at least the following beneficial technical effects: (1) Significant reduction in prestress loss: By establishing a quantitative mapping relationship between prestress loss and turning parameters, and using intelligent optimization algorithms to solve for the optimal parameter combination, the total prestress loss of the variable angle segment can be reduced, effectively improving prestress efficiency.

[0017] (2) The design method is systematic and scientific: This invention establishes a complete optimization design process from parametric modeling, loss calculation, optimization solution to result verification, transforming the existing design method that mainly relies on engineering experience into an optimization design method based on mathematical models.

[0018] (3) Comprehensive consideration of multiple loss factors: The prestress loss calculation model of the present invention simultaneously considers friction loss, anchor deformation and shrinkage loss, concrete elastic compression loss, shrinkage and creep loss and stress relaxation loss, and establishes the correlation between each loss item and the steering parameter.

[0019] (4) Achieve synergistic optimization of structural performance: By introducing structural performance requirements such as overall tower frequency constraints and main column bearing capacity constraints into the constraints, the synergistic optimization of steering parameter design and overall tower structural performance is achieved.

[0020] (5) Strong engineering practicality: The optimal design scheme output by this invention can directly guide the engineering design and prefabrication of the variable angle section of the lattice wind turbine tower, and has strong engineering practical value. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is an overall flowchart of the optimization method of the present invention; Figure 2 This is a simplified structural diagram of a lattice-type wind turbine tower. Figure 3 A flowchart for using a genetic algorithm to solve for the optimal steering parameters; Figure 4 This is a structural block diagram of the lattice tower variable angle section steering parameter optimization system for minimizing prestress loss according to the present invention. Detailed Implementation

[0023] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0024] In the description of this invention, it should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0025] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0027] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0028] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] Example 1 Figure 2 The structural form of a lattice-type wind turbine tower is illustrated, where the variable-angle section includes a prestressed tendon turning channel. This embodiment provides a method for optimizing the turning parameters of the variable-angle section of the lattice tower to minimize prestress loss, including: S1. Establish a parametric model for the turning of prestressed tendons in the variable angle section: Based on the overall design parameters of the lattice wind turbine tower, determine the geometric parameters of the variable angle section and establish a parametric finite element model that includes the geometric feature parameters of the turning channel of the prestressed tendons.

[0030] In this step, the basic geometric parameters of the variable angle segment include: the height of the variable angle segment. , bottom cross-sectional width of the variable angle segment Width of the top section of the variable angle segment The tilt angle of the main column within the angle section and the total turning angle of the prestressing tendons within the angle-changing section. .

[0031] Furthermore, the geometric characteristic parameters of the prestressed tendon turning channel include: the radius of curvature of the turning channel. (A function varying along height z), cross-sectional dimensions of the bell-shaped hole (diameter of the large end) Small end diameter ), contour curve parameters of the smooth inner convex structure (including curve type and curve control parameters).

[0032] Furthermore, the parametric finite element model includes the following components: the outer steel pipe of the main column (simulated using shell elements), the internal concrete (simulated using solid elements), the vertical prestressing tendons (simulated using rod elements or beam elements, with initial prestress applied), and the inner wall of the prestressing tendon turning channel (simulated using contact elements to simulate the frictional contact between the prestressing tendons and the channel wall).

[0033] S2. Determine the design variables: Select at least one parameter from the geometric characteristic parameters of the prestressed tendon turning channel of the variable angle segment as the optimization design variable.

[0034] Preferably, the optimization design variables include one or more combinations of the following parameters: (a) Radius of curvature of the steering channel : is a function of height z, and can be a constant radius of curvature, a linearly varying radius of curvature, a piecewise constant radius of curvature, or a variable radius of curvature described by a spline curve; (b) Dimensional parameters of the bell-shaped hole cross-section: diameter of the large end With small end diameter ratio , And the dimensional variation law of the bell-shaped hole cross section along the height direction of the variable angle section; (c) The contour curve shape of the smooth internal convex structure: including circular arc curve, parabola, catenary or B-spline curve; (d) Length of turning section This refers to the vertical distance between the starting point and the ending point where the prestressed tendon changes direction. (e) Coefficient of friction of the inner wall of the steering channel It depends on the pore material and surface treatment method.

[0035] S3. Construct a prestress loss calculation model: Establish a prestress loss calculation model that considers multiple loss factors, and express the total prestress loss as a function of design variables.

[0036] Total prestress loss It includes the following components: ,in, This refers to the prestress loss caused by anchor deformation and prestressing tendon retraction. This refers to the prestress loss caused by friction between the prestressed tendons and the inner wall of the turning channel (including curvature friction loss and length friction loss). This refers to the loss of prestress caused by the elastic compression of concrete. This refers to the prestress loss caused by the relaxation of prestressing tendons. For prestress loss caused by concrete shrinkage and creep, the calculation methods for the above-mentioned losses shall be carried out in accordance with the relevant provisions of the national standard GB / T 50010.

[0037] S4. Establish an optimized mathematical model: With the minimization of prestress loss as the objective function and structural safety and construction requirements as constraints, establish an optimized mathematical model for the turning parameters of the variable angle segment.

[0038] The objective function is:

[0039] Alternatively, a weighted multi-objective optimization approach can be adopted: Where x is the design variable vector, and C(x) is the cost function related to the manufacturing cost or construction difficulty of the steering channel. and These are the weighting coefficients.

[0040] The constraints include at least one of the following: (1) Upper limit constraint on prestress loss: ; (2) Lower limit constraint of turning curvature radius: ; (3) Constraints on the cross-sectional dimensions of the bell-shaped hole: ; (4) Bending stress constraint of prestressed tendons: ; (5) Contact stress constraint of the inner wall of the steering channel : (6) Length constraint of turning section: ; (7) Overall frequency constraint of the tower: ; (8) Bearing capacity constraint of main column section: According to the design code of steel pipe concrete structure, ensure that the bearing capacity of the main column section in the turning area meets the design requirements.

[0041] S5. Use intelligent optimization algorithms to solve for the optimal combination of steering parameters: Select an intelligent optimization algorithm suitable for nonlinear and multi-constraint optimization problems, and search for the optimal combination of design variables that minimizes the objective function within the constraints.

[0042] Preferably, the intelligent optimization algorithm is one of the following: genetic algorithm, particle swarm optimization algorithm, simulated annealing algorithm, ant colony optimization algorithm, or optimization algorithm based on surrogate model.

[0043] This embodiment uses a genetic algorithm as the intelligent optimization algorithm. The specific optimization solution process is as follows: Figure 2 As shown. Figure 2 The complete process from initial population generation to iteration termination is presented. Based on this process, the solution steps include: S5.1 Initialize the population: Randomly generate N individuals within the range of design variable values. Each individual represents a set of steering parameter combinations and uses real number encoding or binary encoding. S5.2 Fitness Assessment: For each individual in population N, call the prestress loss calculation model in step S3 to calculate the corresponding total prestress loss, and apply a penalty function according to the constraint satisfaction to obtain the fitness value. S5.3 Selection Operation: Based on fitness values, select superior individuals for the next generation using roulette wheel selection or tournament selection methods; S5.4 Crossover operation: based on crossover probability Perform a crossover operation on the selected individuals to generate new individuals; S5.5 Mutation Operation: Based on mutation probability Mutation manipulation of individuals increases population diversity; S5.6 Iteration judgment: Repeat steps S5.2 to S5.5 until the maximum number of iterations is reached or the fitness value converges, and output the optimal solution.

[0044] S6. Verify the structural performance of the optimal solution: Substitute the optimal steering parameter combination obtained in step S5 into the parameterized finite element model established in step S1, and perform refined finite element analysis to verify whether the structural performance of the steering region meets the design requirements.

[0045] Verifying whether the structural performance of the steering area meets the design requirements includes: (1) The stress distribution of prestressed tendons in the turning area should be ensured so that the maximum stress does not exceed the allowable stress; (2) Ensure that the local bearing stress of the concrete inner wall of the turning channel does not exceed the local bearing strength of the concrete; (3) The overall stress and deformation of the main column in the turning area of ​​the variable angle section are ensured to meet the requirements of bearing capacity and stiffness; (4) Comparison and verification of the finite element analysis results and the calculation model results of the total prestress loss.

[0046] S7. Output the optimal design scheme: If step S6 passes the verification, output the optimal combination of variable angle segment steering parameters, including the optimal radius of curvature. Optimal bell-shaped hole cross-sectional parameters Optimal smooth inner convex structure profile curve, optimal turning segment length If the verification fails, adjust the constraints or optimize the algorithm parameters and return to step S5 to solve again.

[0047] Example 2 The method for optimizing the steering parameters of the variable-angle section of the lattice tower to minimize prestress loss provided in this embodiment takes a certain prestressed steel-concrete lattice structure as a reference, with a hub height of 150 meters, a single unit capacity of 5.6MW, and an impeller diameter of 200 meters.

[0048] like Figure 1 As shown, the optimization method of the present invention includes seven core steps.

[0049] Step S1: Establish a parametric model of the orientation of the prestressed tendons in the variable angle segment. In this embodiment, the geometric parameters of the variable angle segment are: , , , , A parametric finite element model was established, which includes the contact relationship between the outer steel pipe of the main column, the inner concrete, the vertical prestressed tendons, and the inner wall of the turning channel. All geometric parameters in the model can be controlled by parametric variables.

[0050] Step S2: Determine design variables In this embodiment, the following parameters are selected as optimization design variables: ,in: A constant radius of curvature is used, ranging from 3.0m to 8.0m. The value range is 1.2 to 2.5. The value range is 3.0m to 8.0m. The value range is 0.15 to 0.30.

[0051] Step S3: Construct a prestress loss calculation model In this embodiment, the prestressed tendons used have a diameter of Low-relaxation steel strand, standard value of tensile strength elastic modulus Tensioning control stress The formula for calculating the total prestress loss shall be in accordance with the national standard GB / T 50010.

[0052] Step S4: Establish an optimization mathematical model In this embodiment, the constraints include: , , , , , .

[0053] Step S5: Use a genetic algorithm to solve for the optimal combination of steering parameters. In this embodiment, a genetic algorithm is used to solve the problem, and the specific parameters are set as follows: population size. Maximum number of iterations Crossover probability Probability of mutation The encoding method uses real numbers, with each individual variable defined by a design variable. The fitness function is composed of real values. ,in The amount of violation of each constraint, This is the penalty coefficient.

[0054] After 200 iterations, the optimization results converged. The optimal combination of steering parameters was obtained as follows: Optimal radius of curvature:

[0055] Optimal bell-shaped aperture cross-section ratio

[0056] Optimal turning segment length

[0057] Optimize friction coefficient

[0058] Step S6: Verify the structural performance of the optimal solution The optimized steering parameters were substituted into the parametric finite element model for refined analysis. The analysis results show that: the maximum stress of the prestressed tendon in the steering area is 1120MPa, which is less than the design requirement of 0.6f_ptk (i.e., 1116MPa); the maximum contact compressive stress of the concrete on the inner wall of the steering channel is 16.8MPa, which is less than the allowable value of 20MPa; the maximum Mises stress of the main column in the variable angle section is 285MPa, which meets the strength design requirements of Q355 steel. The total prestress loss obtained from the finite element analysis was 178 MPa, which is within 3% of the error of the predicted value of 182 MPa from the calculation model, thus verifying the accuracy of the calculation model.

[0059] Compared with conventional experience design schemes ( , , Compared to the previous method, the optimal solution reduces the total prestress loss by approximately 18%.

[0060] Step S7: Output the optimal design scheme The system outputs the optimal combination of steering parameters for variable angle segments, which can be directly used in engineering design and prefabrication of components.

[0061] Example 2 This embodiment is basically the same as Embodiment 1, except that the variable designed in step S2 is a variable radius of curvature function, i.e., radius of curvature. It varies linearly along the height z: ,in, The radius of curvature at the bottom of the variable angle segment is... Let be the radius of curvature at the top of the variable angle segment. The design variable is expanded to... .

[0062] By adopting a variable radius of curvature scheme, the curvature distribution can be flexibly adjusted according to the actual stress requirements of the prestressing tendons at different height positions within the variable angle section. At the bottom of the variable angle section, where the tower cross-section is larger and the prestressing tendons are far from the central axis of the tower, the radius of curvature can be appropriately increased to reduce bending stress; at the top of the variable angle section, where the tower cross-section is smaller, a relatively smaller radius of curvature can be used.

[0063] The same optimization algorithm as in Example 1 was used to solve the problem, and the optimal parameter combination was obtained as follows: , , , , Compared to the constant curvature scheme, the variable curvature scheme further reduces prestress loss by approximately 6%.

[0064] Example 3 like Figure 4 As shown, the lattice tower variable angle segment steering parameter optimization system for minimizing prestress loss provided in this embodiment includes: Parametric finite element model establishment unit: Based on the overall design parameters of the lattice wind turbine tower, determine the geometric parameters of the variable angle section, and establish a parametric finite element model including the geometric feature parameters of the prestressed tendon turning channel; Optimization design variable selection unit: Select at least one parameter from the geometric characteristic parameters of the prestressed tendon turning channel as the optimization design variable; Prestress Loss Calculation Model Establishment Unit: Establish a prestress loss calculation model, and calculate the total prestress loss. The total prestress loss is expressed as a function of the optimized design variables. This includes a combination of various factors such as anchor deformation and prestressed tendon shrinkage loss, friction loss between prestressed tendons and the inner wall of the turning channel, concrete elastic compression loss, concrete shrinkage and creep loss, and prestressed tendon stress relaxation loss. Optimization of mathematical model building unit: Taking the minimization of prestress loss as the objective function and structural safety and construction requirements as constraints, an optimization mathematical model for the turning parameters of the variable angle segment is established; Optimal design variable combination acquisition unit: Based on the optimization mathematical model of the variable angle segment steering parameters, an intelligent optimization algorithm is used to search for the optimal design variable combination that minimizes the objective function within the constraints. Finite element analysis unit: Substitute the optimal design variable combination into the parameterized finite element model to perform refined finite element analysis and verify whether the structural performance of the turning area meets the design requirements; Judgment Unit: If the verification passes, output the optimal combination of steering parameters for the variable angle segment; if the verification fails, adjust the constraints or optimize the algorithm parameters and return to the optimal design variable combination to obtain the unit for re-solving until the verification passes.

[0065] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0066] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for optimizing the turning parameters of a lattice tower with minimized prestress loss, characterized in that, Includes the following steps: S1. Based on the overall design parameters of the lattice wind turbine tower, determine the geometric parameters of the variable angle section and establish a parametric finite element model that includes the geometric feature parameters of the prestressed tendon turning channel. S2. Select at least one parameter from the geometric characteristic parameters of the prestressed tendon turning channel as an optimization design variable; S3. Establish a prestress loss calculation model, and calculate the total prestress loss. The total prestress loss is expressed as a function of the optimized design variables. This includes a combination of various factors such as anchor deformation and prestressed tendon shrinkage loss, friction loss between prestressed tendons and the inner wall of the turning channel, concrete elastic compression loss, concrete shrinkage and creep loss, and prestressed tendon stress relaxation loss. S4. With the minimization of prestress loss as the objective function and structural safety and construction requirements as constraints, establish an optimization mathematical model for the turning parameters of the variable angle segment; S5. Based on the optimization mathematical model of the variable angle segment steering parameters, an intelligent optimization algorithm is used to search for the optimal combination of design variables that minimizes the objective function within the constraints. S6. Substitute the optimal design variable combination into the parameterized finite element model, perform refined finite element analysis, and verify whether the structural performance of the turning area meets the design requirements. S7. If the verification passes, output the optimal combination of steering parameters for the variable angle segment; if the verification fails, adjust the constraints or optimize the algorithm parameters and return to step S5 to solve again until the verification passes.

2. The method for optimizing the turning parameters of a lattice tower with minimized prestress loss according to claim 1, characterized in that, The geometric parameters of the variable angle segment mentioned in step S1 include: the height of the variable angle segment. , bottom cross-sectional width of the variable angle segment Width of the top section of the variable angle segment The tilt angle of the main column within the angle section and the total turning angle of the prestressing tendons within the angle-changing section. .

3. The method for optimizing the turning parameters of a lattice tower with minimized prestress loss according to claim 1, characterized in that, The geometric characteristic parameters of the prestressed tendon turning channel mentioned in step S1 include: the radius of curvature of the turning channel. The cross-sectional dimensions of the bell-shaped hole, the contour curve parameters of the smooth inner convex structure, and the length of the turning section. and the coefficient of friction of the inner wall of the steering channel At least one of them.

4. The method for optimizing the turning parameters of a lattice tower with minimized prestress loss according to claim 3, characterized in that, The cross-sectional dimensions of the bell-shaped hole include: the diameter of the large end. With small end diameter ratio , And the dimensional variation law of the bell-shaped hole cross section along the height direction of the variable angle segment, the contour curve shape of the smooth inner convex structure includes circular arc curve, parabola, catenary or B-spline curve; The radius of curvature of the steering channel Variable curvature radius described by constant curvature radius, linearly varying curvature radius, piecewise constant curvature radius, or spline curve.

5. The method for optimizing the turning parameters of a lattice tower with minimized prestress loss according to claim 1, characterized in that, The prestress loss mentioned in step S3 is calculated according to the formula in standard GB / T 50010.

6. The method for optimizing the turning parameters of a lattice tower with minimized prestress loss according to claim 1, characterized in that, The constraints described in step S4 include at least one of the following: (1) Upper limit constraint on prestress loss: ,in, The upper limit of the allowable prestress loss is specified. (2) Lower limit constraint of turning curvature radius: ,in, The minimum allowable radius of curvature is required to ensure that the prestressed tendons do not experience excessive bending stress and local compressive stress. (3) Constraints on the cross-sectional dimensions of the bell-shaped hole: ,in, The diameter of the prestressing tendon. To meet minimum clearance requirements, The maximum permissible rate of change of cross section; (4) Bending stress constraint of prestressed tendons: ,in, This refers to the additional bending stress generated by the prestressing tendons due to their turning and bending. To allow for bending stress; (5) Contact stress constraint of the inner wall of the steering channel ,in, This refers to the contact compressive stress between the prestressed tendon and the inner wall of the turning channel. For prestressing tendon tension, The allowable compressive stress of the duct material: (6) Length constraint of turning section: ,in, Minimum length of the steering segment to ensure smooth steering transition; (7) Overall frequency constraint of the tower: ,in, The first-order natural frequency of the tower, Minimum permissible frequency to avoid the rotational frequency of the wind turbine and the passing frequency of the blades; (8) Bearing capacity constraints of main column sections.

7. The method for optimizing the turning parameters of a lattice tower with minimized prestress loss according to claim 1, characterized in that, The objective function described in step S4 adopts a weighted multi-objective optimization form: Where F(x) is the overall objective function value, x is the design variable vector, and C(x) is the cost function related to the manufacturing cost or construction difficulty of the steering channel. and These are the weighting coefficients.

8. The method for optimizing the turning parameters of a lattice tower with minimized prestress loss according to claim 1, characterized in that, The intelligent optimization algorithm mentioned in step S5 is one of the following: genetic algorithm, particle swarm optimization algorithm, simulated annealing algorithm, ant colony algorithm, or optimization algorithm based on surrogate model.

9. The method for optimizing the turning parameters of a lattice tower with minimized prestress loss according to claim 1, characterized in that, The verification of whether the structural performance of the turning area meets the design requirements in step S6 includes: stress distribution of prestressed tendons in the turning area, local bearing stress of concrete on the inner wall of the turning channel, overall stress and deformation of the main column of the variable angle section in the turning area, and comparison and verification of the finite element analysis results and calculation model results of the total prestress loss.

10. A system for optimizing the steering parameters of a lattice tower with variable angle sections to minimize prestress loss, characterized in that, include: Parametric finite element model establishment unit: Based on the overall design parameters of the lattice wind turbine tower, determine the geometric parameters of the variable angle section, and establish a parametric finite element model including the geometric feature parameters of the prestressed tendon turning channel; Optimization design variable selection unit: Select at least one parameter from the geometric characteristic parameters of the prestressed tendon turning channel as the optimization design variable; Prestress Loss Calculation Model Establishment Unit: Establish a prestress loss calculation model, and calculate the total prestress loss. The total prestress loss is expressed as a function of the optimized design variables. This includes a combination of various factors such as anchor deformation and prestressed tendon shrinkage loss, friction loss between prestressed tendons and the inner wall of the turning channel, concrete elastic compression loss, concrete shrinkage and creep loss, and prestressed tendon stress relaxation loss. Optimization of mathematical model building unit: Taking the minimization of prestress loss as the objective function and structural safety and construction requirements as constraints, an optimization mathematical model for the turning parameters of the variable angle segment is established; Optimal design variable combination acquisition unit: Based on the optimization mathematical model of the variable angle segment steering parameters, an intelligent optimization algorithm is used to search for the optimal design variable combination that minimizes the objective function within the constraints. Finite element analysis unit: Substitute the optimal design variable combination into the parameterized finite element model to perform refined finite element analysis and verify whether the structural performance of the turning area meets the design requirements; Judgment Unit: If the verification passes, output the optimal combination of steering parameters for the variable angle segment; if the verification fails, adjust the constraints or optimize the algorithm parameters and return to the optimal design variable combination to obtain the unit for re-solving until the verification passes.

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