A calculation method for the dynamic response of a pure float-type photovoltaic array

Abstract

The present invention discloses a method for calculating the dynamic response of a pure floating photovoltaic array to reduce the calculation time and cost. The method includes: determining the minimum repeating module of the pure floating photovoltaic array; determining the numerical equivalent body of the pure floating photovoltaic array, constructing a three-dimensional digital model of the numerical equivalent body and simplifying it; establishing an optimal numerical equivalent body simulation model according to the working conditions and environmental loads of the pure floating photovoltaic array and the simplified three-dimensional digital model of the numerical equivalent body, and calculating the hydrodynamic coefficients and wind and flow force coefficients of a single optimal numerical equivalent body simulation model; determining the connection structure and mechanical parameters between the numerical equivalent bodies, and establishing a numerical model under the overall size of the array; performing time-domain numerical simulation under corresponding working conditions to obtain the motion response results. The present invention introduces the concepts of the minimum repeating module and the numerical equivalent body, which can quickly calculate large-scale pure floating photovoltaic arrays, improve the calculation efficiency, and reduce the calculation cost.

Description

Technical Field

[0001] The present invention relates to the technical field of marine new energy, and more specifically, to a method for calculating the dynamic response of a pure float-type photovoltaic array. Background Art

[0002] China has vast offshore areas and rich resources such as lakes and reservoirs, having natural advantages for the development of floating photovoltaics. The floating photovoltaic system has advantages such as high power generation, environmental protection, and land saving. Therefore, the application of the floating photovoltaic system should be vigorously promoted.

[0003] The floating photovoltaic system is divided into the following forms according to the design scheme of the floating body: platform type, thin film type, and pure float type. Among them, the pure float type directly supports the photovoltaic panels using floating bodies, and its structural composition can be divided into a modular float structure, a bolt connection structure, a photovoltaic module structure, and a mooring system structure. The pure float-type photovoltaic system has the following advantages: easy to manufacture, transport, and install; almost no metal parts, with high corrosion resistance; through non-rigid connections, reducing the wind, wave, and current loads of the system.

[0004] At the present stage, the research on the pure float-type photovoltaic array focuses on aspects such as the optimization of the float structure, the influence of the mechanical parameters of the connection structure on the wave load of the float, and the wind load of the photovoltaic structure. Current research all focuses on the influence of a single structure of the pure float-type photovoltaic array on the motion response of a small photovoltaic array. Moreover, when the existing methods are applied to the calculation of the overall motion response of the array, a large number of hydrodynamic calculations with multiple degrees of freedom are required, the calculation is very time-consuming, the efficiency is low, and it is difficult to couple the simultaneous action of wind, waves, and currents. In actual engineering, the pure float-type photovoltaic array is an entire system in which various structures are coupled and interact with each other, and the existing methods have poor simulation effects. And as the floating photovoltaic system gradually develops towards the ocean, the pure float-type photovoltaic array will be exposed to huge wind, wave, and current loads, and the calculation results often have a certain gap from the actual situation, affecting the accuracy of the calculation results and restricting the development of the floating photovoltaic system. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art, and provide a method for calculating the dynamic response of a pure float-type photovoltaic array to reduce the calculation time and cost.

[0006] The technical solution adopted to achieve the purpose of the present invention is as follows:

[0007] A method for calculating the dynamic response of a pure float-type photovoltaic array includes the following steps:

[0008] S1. Determine the minimum repeating module of the pure float-type photovoltaic array;

[0009] S2. Determine the numerical equivalent of the pure floating photovoltaic array according to the composition and minimum repeating module of the pure floating photovoltaic array structure, construct a three-dimensional digital model of the numerical equivalent and simplify it to obtain a simplified three-dimensional digital model of the numerical equivalent;

[0010] S3. Based on the operating conditions and environmental loads of the pure floating photovoltaic array, and the simplified three-dimensional digital model of the numerical equivalent obtained in step S2, establish an optimal numerical equivalent simulation model, and calculate the hydrodynamic coefficients, wind and flow force coefficients of a single optimal numerical equivalent simulation model;

[0011] S4. According to the actual connection situation of the pure floating photovoltaic array, use the hydrodynamic coefficients, wind and flow force coefficients of a single optimal numerical equivalent simulation model obtained in step S3 to determine the connection structure and mechanical parameters between the numerical equivalents, and establish a numerical model under the overall size of the array;

[0012] S5. Conduct time-domain numerical simulation under the corresponding working conditions on the numerical model under the overall size of the array obtained in step S4 to obtain the motion response results of the pure floating photovoltaic array.

[0013] It further includes step S6, and the step S6 is: taking the motion response results of the whole array as displacement boundary conditions, conduct strength analysis on the connection structure, mooring system, and photovoltaic module support structure.

[0014] The step S2 includes the following steps:

[0015] S21. Take 1 / k of the wave length in the long side direction of the array under the target working condition as the characteristic length λ, the initial value of k is 20, determine that the division interval of the long side of the array is n minimum repeating modules, n≥1, and the determination method of n is based on the formula n = FLOOR(λ / a), where FLOOR() is the floor function, and a is the side length in the corresponding direction of the minimum repeating module; similarly, take out that the division interval of the short side of the array is m minimum repeating modules, so as to obtain a small array composed of n×m minimum repeating modules;

[0016] S22. Consider the connection between the minimum repeating modules in the small array as a rigid connection, and on the premise of ensuring that the draft and waterplane area of the model remain unchanged, establish a numerically reasonable simplified model of the small array in appearance, that is, the numerical equivalent;

[0017] S23. Import the numerical models of the numerical equivalent and the small array composed of the minimum repeating modules into the hydrodynamic calculation software respectively, and calculate their hydrodynamic performance under the target working condition;

[0018] S24. Compare the obtained hydrodynamic performance. If the comparison result does not meet the expectation, return to step S21, let k = k + 1, and change the selection result of the numerical equivalent body; if the comparison result meets the expectation, use this numerical equivalent body model as the simplified three-dimensional digital model of the numerical equivalent body.

[0019] The said step S3 includes the following steps:

[0020] S31. Import the simplified three-dimensional digital model of the numerical equivalent body into the finite element simulation software;

[0021] S32. Set the corresponding environmental parameters according to the working conditions and environmental loads of the pure buoyant photovoltaic array;

[0022] S33. Establish an optimal numerical equivalent body simulation model, and calculate the hydrodynamic coefficients and wind and flow force coefficients of a single numerical equivalent body simulation model in the frequency domain.

[0023] Step S4 includes the following steps:

[0024] S41. Calculate the mechanical properties of the connection structure and simplify it into a spherical hinge connection with different rotational freedom angle stiffnesses;

[0025] S42. Input the hydrodynamic coefficients and wind and flow force coefficients of the single optimal numerical equivalent body simulation model obtained in step S3 into the simulation software;

[0026] S43. According to the structural form of the pure buoyant photovoltaic array, set the mooring arrangement, anchoring arrangement, and numerical equivalent body connection method to obtain a numerical model under the overall size of the array;

[0027] Among them, step S41 includes the following steps:

[0028] S411. According to the structural form of the pure buoyant photovoltaic array, determine the connection structure form and connection quantity between numerical equivalent bodies;

[0029] S412. Establish a three-dimensional digital model of the connection structure;

[0030] S413. Import the three-dimensional digital model of the connection structure into the finite element simulation software;

[0031] S414. In the simulation software, endow the material properties of the connection structure and calculate the mechanical properties of a single connection structure;

[0032] S415. According to the mechanical properties of a single connection structure and the connection quantity and arrangement method of the connection structure between numerical equivalent bodies, determine the arrangement direction and quantity of the connectors between optimal numerical equivalent bodies; The connection of six modules between optimal numerical equivalent bodies is simplified into a spherical hinge with different rotational freedom angle stiffnesses.

[0033] Step S6 includes the following steps:

[0034] S61. Determine the connection structure, mooring system, photovoltaic module support structure to be checked, and material parameters, and establish finite element models for them respectively;

[0035] S62. Use the motion response results of the pure buoyant photovoltaic array obtained in step S5 as the displacement boundary conditions for the structure to be analyzed;

[0036] S63. According to the displacement boundary conditions, perform finite element strength calculation on the structure to be checked, and obtain the stress and strain results of the structure under the working conditions.

[0037] Analyze the connection structure, mooring system, and photovoltaic module support structure from the following aspects respectively:

[0038] S631. The connection structure strength analysis includes the following steps:

[0039] S6311. Determine the position information of the connection structure to be analyzed;

[0040] S6312. Obtain the relative displacement of the two ends of the buoy of the connection structure to be analyzed according to the dynamic response results of the pure buoyant photovoltaic array, and use it as the displacement boundary condition for the strength calculation of the connection structure;

[0041] S6313. Run the finite element calculation software to calculate the stress and strain distribution of the connection structure;

[0042] S632. The mooring system analysis includes the following steps:

[0043] S6321. Determine the position information of the mooring system to be analyzed;

[0044] S6322. Obtain the displacements of the two ends of the buoy and the anchoring system of the mooring system to be analyzed according to the dynamic response results of the pure buoyant photovoltaic array, and use them as the displacement boundary conditions for the mooring system analysis and calculation;

[0045] S6323. Establish a three-dimensional digital model of the mooring system;

[0046] S6324. Run the finite element simulation software to calculate the failure probability of the mooring cable unit, that is, the exceedance probability of exceeding its maximum breaking tension, whether the gravity anchoring unit has displacement, and the strength check of the mooring cable-floating body connection component;

[0047] S633. The photovoltaic module support structure analysis includes the following steps:

[0048] S6331. Determine the position information of the photovoltaic module support structure to be analyzed;

[0049] S6332. Obtain the displacement of the float at the lower end of the support structure of the photovoltaic module to be analyzed based on the dynamic response result of the pure float-type photovoltaic array, and use it as the displacement boundary condition of the support structure of the photovoltaic module;

[0050] S6333. Determine whether adjacent support structures of photovoltaic modules collide. If they collide, proceed to step S6334; if not, end the analysis;

[0051] S6334. Run finite element calculation software to obtain the damage result of the support structure of the photovoltaic module.

[0052] The minimum repeating module has the following characteristics: it appears repeatedly in the photovoltaic array system, has a unified structural composition form, unified structural functions, unified material properties, and cannot be further divided into smaller repeating structures.

[0053] The beneficial effects of the present invention are as follows:

[0054] 1. According to the characteristics of the pure float-type photovoltaic array with a simple structural form and high repetition rate, the present invention introduces the concepts of the minimum repeating module and the numerical equivalent body, simplifies the array composed of multiple minimum repeating modules into a numerical equivalent body similar in hydrodynamic performance, wind force coefficient, and flow force coefficient, can quickly calculate the large-scale pure float-type photovoltaic array, obtain the overall motion response of the array, improve the calculation efficiency, and reduce the calculation cost.

[0055] 2. While ensuring the calculation speed, the present invention improves the accuracy of the simplified model; at the same time, using the overall motion response of the array as the boundary condition and combining with the finite element analysis software of the structure to be analyzed, calculate the aspects to be optimized for each structure, which can help designers better understand and optimize the design of the pure float-type photovoltaic array, improve the quality and efficiency of the design, and further improve the performance of the pure float-type photovoltaic array, improve the reliability of the design, and provide decision-making support.

[0056] 3. Through the simulation model, the present invention enables the performance of the pure float-type photovoltaic array under various working conditions to be simulated and tested in the initial design stage, which helps to more accurately predict the hydrodynamic performance and structural reliability of the pure float-type photovoltaic array, reduce the number of design modifications and tests, and further ensure that the obtained design scheme meets the preset usage conditions and performance requirements, enhancing the reliability of the design. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 The figure shows the flow chart of the dynamic response calculation method of the pure float-type photovoltaic array of the present invention;

[0058] Figure 2 The figure shows the overall structural schematic diagram of the pure float-type photovoltaic array system;

[0059] Figure 3 Shown is a schematic diagram of the arrangement and connection form of a photovoltaic array in a pure floating photovoltaic array system;

[0060] Figure 4 Shown is a schematic diagram of the simplified form of a pure floating photovoltaic array;

[0061] Figure 5 Shown is a schematic diagram of the finite element simulation model of the connection structure in a pure floating photovoltaic array system. Specific embodiments

[0062] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments.

[0063] The flowchart of the dynamic response calculation method for the pure floating photovoltaic array of the present invention is as Figure 1 shown, and the dynamic response calculation method for the pure floating photovoltaic array includes the following steps:

[0064] S1. Determine the minimum repeating module of the pure floating photovoltaic array according to the relevant parameters of the pure floating photovoltaic array to be analyzed and the geometric characteristics of the structure of the pure floating photovoltaic array system.

[0065] The minimum repeating module has the following characteristics: it appears repeatedly in the photovoltaic array system, has a unified structural composition form, unified structural functions, unified material properties, and cannot be further divided into smaller repeating structures.

[0066] Among them, the relevant parameters of the pure floating photovoltaic array include the overall parameters of the photovoltaic array (including the main dimensions, total displacement, mooring system layout scheme, etc. of the pure floating photovoltaic array), various floating body unit parameters (including floating body dimensions, material parameters, connection methods, etc.), mooring parameters (including mooring cable dimensions, mooring layout methods, mooring cable materials, etc.), anchoring parameters (including anchoring types, anchoring layout forms, anchoring point water depths, etc.), photovoltaic support component parameters (including the structural form, material parameters, fixing methods, etc. of the photovoltaic support components), and photovoltaic panel parameters (structural form, weight, moment of inertia, layout method, etc.).

[0067] The structural schematic diagram of the pure floating photovoltaic array system of this embodiment is as Figure 2 shown. The structural composition of the pure floating photovoltaic array system includes a mooring system composed of multiple anchoring units, a floating body system composed of multiple floating body units, a photovoltaic system composed of several photovoltaic components, and a connection system. Among them, each anchoring unit includes a gravity anchor 11, a mooring cable 12, and a mooring cable - floating body connection component 13. Each floating body unit includes an equipment floating body 21, a main floating body 22, and a secondary floating body 23. Each photovoltaic component includes a photovoltaic panel 31 and a photovoltaic support component 32. The connection system includes several connection bolts 41. The arrangement and connection form of the pure floating photovoltaic array is as Figure 3As shown in the figure, two main floating bodies 22 and two equipment floating bodies 21 are connected into one body by connecting bolts 41 through the prefabricated hole positions of each floating body. A photovoltaic module is fixed on the two equipment floating bodies 21 to form the minimum repeating module 51. The minimum repeating module 51 is as shown in Figure 3 the dotted line in the figure. The adjacent minimum repeating modules 51 are connected to each other by auxiliary floating bodies 23 through connecting bolts 41 to finally form an array structure. The floating body hole positions on the outer side of the array structure are used to connect the mooring cable-floating body connection assembly 13 in the anchoring system. The mooring cable 12 is fixed on the mooring cable-floating body connection assembly 13, and the other end of the mooring cable is fixed to the gravity anchor 11.

[0068] S2. According to the composition of the pure floating photovoltaic array structure and the minimum repeating module, determine the numerical equivalent body of the pure floating photovoltaic array. Using computer-aided design technology, construct a three-dimensional digital model of the numerical equivalent body and perform structural simplification on it.

[0069] Among them, the numerical equivalent body is the component unit of the equivalent model obtained by reasonably dividing and simplifying the array in the numerical calculation process.

[0070] Step S2 of this embodiment includes the following steps:

[0071] S21. Take 1 / k of the wave length in the long side direction of the array under the target working condition as the characteristic length λ, the initial value of k is 20, and determine that the division interval of the long side of the array is n minimum repeating modules (n≥1). The determination method of n is based on the formula n = FLOOR(λ / a), where FLOOR() is the floor function and a is the side length in the corresponding direction of the minimum repeating module. Similarly, take out the division interval of the short side of the array as m minimum repeating modules, so as to obtain a small array composed of n×m minimum repeating modules.

[0072] Preferably, in this specific embodiment, 3×3 minimum repeating modules are selected to form a small array.

[0073] S22. Consider the connection between the minimum repeating modules in the small array as a rigid connection. On the premise of ensuring that the draft and the waterplane area remain unchanged, establish a numerically simplified model that is reasonable in appearance for the small array, that is, the numerical equivalent body.

[0074] In this embodiment, the simplification content of the small matrix includes:

[0075] As shown in Figure 4 the figure, according to the number and arrangement of the minimum repeating modules in the small matrix, the connecting bolts 41 within a single small matrix are equivalent to rigid connections, that is, a single small matrix is regarded as a rigid floating body. On the premise of ensuring that the draft and the waterplane area remain unchanged, simplify the waterplane cross-sectional shape to reduce the complexity of hydrodynamic performance calculation.

[0076] Specifically, select the 3D modeling software SolidWorks to construct the basic geometric framework of the simplified numerical equivalent body, including the main dimensions of the numerical equivalent body, that is, a single numerical equivalent body contains a small array composed of 3*3 minimum repeating modules. On the basis of the basic framework, optimize the specific shape and structure of the numerical equivalent body, such as the shape of the waterplane section, the array arrangement method, etc., to obtain the 3D digital model of the numerical equivalent body. And construct the 3D digital model of the small array composed of the minimum repeating modules for subsequent hydrodynamic analysis.

[0077] S23. Import the 3D digital models of the numerical equivalent body and the small array composed of the minimum repeating modules into the hydrodynamic calculation software ANSYS AQWA respectively, and calculate their hydrodynamic performance under the target working conditions.

[0078] Specifically, import the 3D digital models of the numerical equivalent body and the small array composed of the minimum repeating modules into the hydrodynamic analysis software ANSYS AQWA respectively, and establish simulation models. Among them, the numerical equivalent simulation model and the small array simulation model composed of the minimum repeating modules have the same main dimensions, mooring form, wind-wave-current environmental parameters, etc., that is, only the 3D digital models are different. Calculate the simulation models to obtain the hydrodynamic performances such as the first-order and second-order wave forces, seakeeping performance, and stability of both.

[0079] S24. Compare the obtained hydrodynamic performances. If the comparison results do not meet the expectations, return to step S21, let k = k + 1, and change the selection result method or the simplification method of the numerical equivalent body until the comparison results meet the expectations of the hydrodynamic performance, and obtain the 3D digital model of the simplified numerical equivalent body.

[0080] S3. According to the working conditions and environmental loads of the pure floater-type photovoltaic array, and the 3D digital model of the simplified numerical equivalent body obtained in step S2, establish the optimal numerical equivalent body simulation model, and calculate the hydrodynamic coefficients and wind and current force coefficients of a single optimal numerical equivalent body simulation model.

[0081] In this embodiment, step S3 includes the following steps:

[0082] S31. Import the 3D digital model of the simplified numerical equivalent body into the finite element simulation software ABAQUS.

[0083] S32. Set the corresponding environmental parameters according to the working conditions and environmental loads of the pure floater-type photovoltaic array.

[0084] S33. In the simulation software, based on the imported 3D digital model of the numerical equivalent body and the set environmental parameters, establish the optimal numerical equivalent body simulation model, and calculate the complete hydrodynamic performance, wind force coefficient, and current force coefficient of a single optimal numerical equivalent body model in the frequency domain.

[0085] S4. According to the actual connection situation of the pure floater-type photovoltaic array, using the hydrodynamic coefficients and wind and current force coefficients of the single optimal numerical equivalent body simulation model obtained in step S3, determine the connection structure and mechanical parameters between the numerical equivalent bodies, and establish a numerical model under the overall size of the array.

[0086] In this embodiment, step S4 includes the following steps:

[0087] S41. Calculate the mechanical properties of the connection structure and simplify it into a spherical hinge connection with different corner stiffnesses for three rotational degrees of freedom.

[0088] It includes the following steps:

[0089] S411. According to the structural form of the pure floater-type photovoltaic array, determine the connection structure form and the number of connections between the numerical equivalent bodies;

[0090] S412. Establish a three-dimensional digital model of the connection structure;

[0091] S413. Import the three-dimensional digital model of the connection structure into the finite element simulation software; in this embodiment, the finite element simulation model selects ABAQUS;

[0092] S414. In the simulation software, based on the material properties assigned to the connection structure and the three-dimensional digital model, establish a simulation model and calculate the mechanical properties of a single connection structure;

[0093] Specifically, as Figure 5 shown is the finite element simulation model of the connection structure established in ABAQUS, where 61 is the three-dimensional model of the secondary floating body unit, 62 is the three-dimensional model of the main floating body unit, and 63 is the three-dimensional model of the connecting bolt unit; the material parameters are all selected as low-density polyethylene materials; at the same time, the mesh density of the connecting bolt unit is encrypted to improve the calculation accuracy.

[0094] S415. According to the mechanical properties of a single connection structure and the number and arrangement method of the connection structures between the numerical equivalent bodies, determine the optimal simplified connection method, arrangement direction and number between the numerical equivalent bodies. Preferably, as Figure 4 shown, the connecting bolt 41 between the optimal numerical equivalent bodies is simplified into a spherical hinge with different corner stiffnesses for three rotational degrees of freedom. This spherical hinge has the same constraint effect on the relative movement between the original connection results and the numerical equivalent bodies.

[0095] S42. Import the hydrodynamic coefficients, wind force coefficients and current force coefficients of the single optimal numerical equivalent body model into the simulation software OrcaFlex;

[0096] S43. Set the mooring arrangement, anchoring arrangement, and numerical equivalent body connection method according to the structure of the pure buoyant photovoltaic array to obtain a numerical model under the overall size of the array;

[0097] S5. Conduct time-domain numerical simulation on the numerical model under the overall size of the array under corresponding working conditions to obtain the motion response results of the array.

[0098] S6. Use the motion response results of the entire array as displacement boundary conditions to conduct strength analysis on the connection structure, mooring system, and photovoltaic module support structure.

[0099] In this embodiment, step S6 includes the following steps:

[0100] S61. Determine the connection structure, mooring system, photovoltaic module support structure, and material parameters to be checked, and establish finite element models for them respectively;

[0101] S62. Use the motion response results of the pure buoyant photovoltaic array obtained in step S5 as the displacement boundary conditions of the structure to be analyzed;

[0102] S63. According to the displacement boundary conditions, conduct finite element strength calculation on the structure to be checked to obtain the stress and strain results of the structure under the working conditions.

[0103] Analyze the connection structure, mooring system, and photovoltaic module support structure from the following aspects respectively:

[0104] S631. The connection structure strength analysis includes the following steps:

[0105] S6311. Determine the position information of the connection structure to be analyzed;

[0106] S6312. Obtain the relative displacement of the two buoys at both ends of the connection structure to be analyzed according to the dynamic response results of the pure buoyant photovoltaic array, and use it as the displacement boundary condition for the strength calculation of the connection structure;

[0107] Specifically, the displacement boundary condition refers to: the motion time history results of the six degrees of freedom of the optimal numerical equivalent bodies on both sides of the connection, and this result is used to calculate the time history results of the rotation angles on the three rotational degrees of freedom of the connection ball joint.

[0108] S6313. According to the simulation model in the simulation software in step S414, and at the same time according to the dynamic response results of the pure buoyant photovoltaic array, set the boundary conditions and initial conditions of the simulation model, run the finite element software, and calculate the stress and strain distribution of the connection structure.

[0109] S632. The mooring system analysis includes the following steps:

[0110] S6321. Determine the position information of the mooring system to be analyzed;

[0111] S6322. Obtain the displacements of the floats at both ends of the mooring system to be analyzed and the anchoring system based on the dynamic response results of the pure float-type photovoltaic array, which are used as the displacement boundary conditions for the analysis and calculation of the mooring system.

[0112] S6323. Establish a three-dimensional digital model of the mooring system; wherein, the mooring system is composed of multiple anchoring units, and each anchoring unit includes a gravity anchor 11, a mooring cable 12, and a mooring cable-float connection assembly 13.

[0113] S6324. In the simulation software OrcaFlex, based on the three-dimensional digital model of the mooring system, establish a simulation model; according to the dynamic response results of the pure float-type photovoltaic array, set the boundary conditions and initial conditions of the simulation model; after setting the environmental parameters, boundary conditions, and initial conditions, run the finite element calculation software for simulation, and calculate the failure probability of the mooring cable unit, that is, the exceedance probability of exceeding its maximum breaking tension, whether the gravity anchoring unit undergoes displacement, and the strength check of the mooring cable-float connection assembly.

[0114] S633. The analysis of the photovoltaic module support structure includes the following steps:

[0115] S6331. Determine the position information of the photovoltaic module support structure to be analyzed.

[0116] S6332. Obtain the displacement of the float at the lower end of the photovoltaic module support structure to be analyzed based on the dynamic response results of the pure float-type photovoltaic array, which is used as the displacement boundary condition of the photovoltaic module support structure.

[0117] S6333. Judge whether adjacent photovoltaic module support structures collide. If they collide, go to step S6334; if they do not collide, end the analysis.

[0118] S6334. Establish a three-dimensional digital model of the photovoltaic module support structure; in the simulation software, based on the material properties and three-dimensional digital model of the photovoltaic module support structure, establish a simulation model; according to the dynamic response results of the pure float-type photovoltaic array, set the boundary conditions and initial conditions of the simulation model; after setting the environmental parameters, boundary conditions, and initial conditions, run the finite element calculation software for simulation to obtain the damage results of the photovoltaic module support structure.

[0119] According to the characteristics of a pure floating photovoltaic array, such as high modularity, a huge number of modules, and high structural repeatability, the present invention proposes a method for calculating the dynamic response of a pure floating photovoltaic array. By introducing the concepts of the minimum repeating module and the numerical equivalent body, the array composed of multiple minimum repeating modules is simplified into a numerical equivalent body similar in hydrodynamic performance, wind force coefficient, and flow force coefficient. This enables rapid calculation of large-scale pure floating photovoltaic arrays, obtaining the overall motion response of the array, improving the calculation efficiency, and reducing the calculation cost. While ensuring the calculation speed, the accuracy of the simplified model is improved; at the same time, using the overall motion response of the array as the boundary condition and combining with the finite element analysis software of the structure to be analyzed, the aspects to be optimized for each structure are calculated, which can help designers better understand and optimize the design of the pure floating photovoltaic array, improve the quality and efficiency of the design, and further improve the performance of the pure floating photovoltaic array, enhance the reliability of the design, and provide decision-making support.

[0120] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for calculating the dynamic response of a pure float photovoltaic array, characterized in that: The steps include: S1. Determine the minimum repeating module of a pure floating photovoltaic array; S2. According to the structure composition and minimum repeating module of the pure floating photovoltaic array, determine the numerical equivalent of the pure floating photovoltaic array, construct a three-dimensional digital model of the numerical equivalent and simplify it to obtain a simplified three-dimensional digital model of the numerical equivalent; S3, according to the working conditions and environmental loads of the pure floating photovoltaic array and the simplified three-dimensional digital model of the numerical equivalent body obtained in step S2, an optimal numerical equivalent body simulation model is established, and the hydrodynamic coefficients and wind and flow coefficients of a single optimal numerical equivalent body simulation model are calculated; S4. According to the actual connection situation of the pure floating photovoltaic array, the hydrodynamic coefficients and wind and flow coefficients of the single optimal numerical equivalent body simulation model obtained in step S3 are used to determine the connection structure and mechanical parameters between the numerical equivalent bodies, and establish a numerical model under the overall size of the array; S5. Performing time domain numerical simulation under corresponding working conditions on the numerical model of the array under the overall size obtained in step S4 to obtain the motion response result of the pure float type photovoltaic array.

2. The method for calculating the dynamic response of a pure floating photovoltaic array according to claim 1, characterized in that: The method further includes step S6, wherein the step S6 is: using the motion response result of the entire array as the displacement boundary condition, performing strength analysis on the connection structure, the mooring system, and the photovoltaic module support structure.

3. The method for calculating the dynamic response of a pure floating photovoltaic array according to claim 1 or 2, characterized in that: The step S2 comprises the following steps: S21. Take 1 / k of the wave length in the direction of the long side of the array under the target working condition as the characteristic length λ, the initial value of k is 20, determine that the long side of the array is divided into n minimum repeating modules, n ≥ 1, and the method for determining n is based on the formula n = FLOOR (λ / a), where FLOOR () is a rounding function, and a is the length of the side in the corresponding direction of the minimum repeating module; similarly, take out the division interval of the short side of the array into m minimum repeating modules, so as to obtain a small array composed of n×m minimum repeating modules; S22. Considering the connection between the smallest repeating modules in the small array as a rigid connection, and ensuring that the draft and waterline area of ​​the model remain unchanged, a numerical model of the small array that is reasonably simplified in appearance, i.e., a numerical equivalent, is established; S23, respectively importing the numerical equivalent body and the numerical model of the small array composed of the minimum repeating module into the hydrodynamic calculation software to calculate the hydrodynamic performance under the target working condition; S24. Compare the obtained hydrodynamic performance. If the comparison result does not meet the expectation, return to step S21, set k=k+1, and change the selection result of the numerical equivalent body; if the comparison result meets the expectation, use the numerical equivalent body model as the simplified numerical equivalent body three-dimensional digital model.

4. The method for calculating the dynamic response of a pure floating photovoltaic array according to claim 1 or 2, characterized in that: The step S3 comprises the following steps: S31, importing the simplified numerical equivalent three-dimensional digital model into finite element simulation software; S32, setting corresponding environmental parameters according to the working conditions and environmental loads of the pure floating photovoltaic array; S33. Establish an optimal numerical equivalent body simulation model, and calculate the hydrodynamic coefficients and wind and flow coefficients of a single numerical equivalent body simulation model in the frequency domain.

5. The method for calculating the dynamic response of a pure floating photovoltaic array according to claim 1 or 2, characterized in that: Step S4 includes the following steps: S41. Calculate the mechanical properties of the connection structure and simplify it into a spherical joint connection with three rotational degrees of freedom and different angular stiffnesses; S42, inputting the hydrodynamic coefficients and wind and flow coefficients of the single optimal numerical equivalent body simulation model obtained in step S3 into the simulation software; S43. According to the pure floating photovoltaic array structure, a mooring arrangement, an anchoring arrangement, and a numerical equivalent body connection method are set to obtain a numerical model under the overall size of the array; Wherein, step S41 comprises the following steps: S411. Determine the connection structure and number of connections between numerical equivalent bodies according to the structure of the pure floating photovoltaic array; S412, establishing a three-dimensional digital model of the connection structure; S413, importing the three-dimensional digital model of the connection structure into finite element simulation software; S414. In the simulation software, the material properties of the connection structure are assigned and the mechanical properties of the single connection structure are calculated; S415. Determine the optimal layout direction and quantity of connectors between numerical equivalent bodies based on the mechanical properties of a single connection structure and the number and layout of connection structures between numerical equivalent bodies. The six module connections between the optimal numerical equivalent bodies are simplified into a ball joint with three rotational degrees of freedom and different angular stiffnesses.

6. The method for calculating the dynamic response of a pure floating photovoltaic array according to claim 2, characterized in that: The step S6 comprises the following steps: S61. Determine the connection structure, mooring system, photovoltaic module support structure, and material parameters to be verified, and establish finite element models for them respectively; S62, using the pure float type photovoltaic array motion response result obtained in step S5 as the displacement boundary condition of the structure to be analyzed; S63. According to the displacement boundary conditions, finite element strength calculation is performed on the structure to be checked to obtain the stress and strain results of the structure under the working condition.

7. The method for calculating the dynamic response of a pure float photovoltaic array according to claim 6, characterized in that: The connection structure, mooring system and photovoltaic module support structure are analyzed from the following perspectives: S631, the strength analysis of the connection structure includes the following steps: S6311, determining the location information of the connection structure to be analyzed; S6312. According to the dynamic response results of the pure float type photovoltaic array, the relative displacement of the floats at both ends of the connection structure to be analyzed is obtained as the displacement boundary condition for the strength calculation of the connection structure; S6313. Run finite element calculation software to calculate the stress and strain distribution of the connection structure; S632, Mooring system analysis includes the following steps: S6321. Determine the position information of the mooring system to be analyzed; S6322. According to the dynamic response results of the pure float type photovoltaic array, the displacements of the floats and anchoring systems at both ends of the mooring system to be analyzed are obtained as the displacement boundary conditions for the mooring system analysis and calculation; S6323. Establish a three-dimensional digital model of the mooring system; S6324. Run the finite element simulation software to calculate the failure probability of the mooring cable unit, that is, the probability of exceeding its maximum breaking tension, whether the gravity anchor unit is displaced, and the strength check of the mooring cable-floating body connection assembly; S633, PV module support structure analysis includes the following steps: S6331. Determine the position information of the supporting structure of the photovoltaic module to be analyzed; S6332. According to the dynamic response result of the pure float type photovoltaic array, the displacement of the float at the lower end of the photovoltaic module support structure to be analyzed is obtained as the displacement boundary condition of the photovoltaic module support structure; S6333, determining whether adjacent photovoltaic module support structures collide, if so, proceed to step S6334, if not, terminate the analysis; S6334. Run the finite element calculation software to obtain the damage results of the photovoltaic module support structure.

8. The method for calculating the dynamic response of a pure floating photovoltaic array according to claim 1, characterized in that: The minimal repeating module has the following characteristics: It appears repeatedly in the photovoltaic array system, has a unified structural composition, unified structural functions, unified material properties, and cannot be divided into smaller repeating structures.

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