Dynamic response calculation method of pure float type photovoltaic array

Abstract

The invention discloses a dynamic response calculation method of a pure float type photovoltaic array, so as to reduce calculation time and cost. Comprising the following steps: determining a minimum repetitive module of the pure float type photovoltaic array; determining a numerical value equivalent body of the pure float type photovoltaic array, and constructing and simplifying a numerical value equivalent body three-dimensional digital model; according to the working condition and the environment load of the pure float type photovoltaic array and the simplified numerical equivalent three-dimensional digital model, establishing an optimal numerical equivalent simulation model, and calculating a hydrodynamic coefficient and a wind and flow force coefficient of a single optimal numerical equivalent simulation model; connection structures and mechanical parameters between numerical equivalent bodies are determined, and a numerical model under the overall size of the array is established; and performing time domain numerical simulation under a corresponding working condition to obtain a motion response result. According to the method, the concept of the minimum repetition module and the numerical equivalent is introduced, the large pure float type photovoltaic array can be calculated quickly, the calculation efficiency is improved, and the calculation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of marine new energy technology, and more specifically, to a dynamic response calculation method for a pure floating photovoltaic array. Background Art

[0002] my country has vast offshore areas and abundant resources such as lakes and reservoirs, which gives it a natural advantage in developing waterborne photovoltaics. Floating photovoltaic systems have the advantages of high power generation, environmental protection, and land conservation. Therefore, the application of floating photovoltaic systems should be vigorously promoted.

[0003] Floating photovoltaic systems are divided into the following types according to the design of the floating body: platform type, membrane type, and pure float type. The pure float type uses a floating body to directly support the photovoltaic panels, 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 photovoltaic system has the following advantages: easy to make, transport, and install; almost no metal parts are used, and it has high corrosion resistance; through non-rigid connections, the wind and wave loads of the system are reduced.

[0004] At present, the research on pure floating photovoltaic arrays focuses on the optimization of floating structures, the influence of mechanical parameters of connecting structures on floating wave loads, and wind loads on photovoltaic structures. Current research focuses on the influence of a single structure on the motion response of a small photovoltaic array in a pure floating photovoltaic array. When the existing methods are applied to the calculation of the overall motion response of the array, a large number of multi-degree-of-freedom hydrodynamic calculations are required. The calculations are very time-consuming and inefficient, and it is difficult to couple the wind, waves and currents at the same time. In actual engineering, a pure floating photovoltaic array is a whole system in which multiple structures are coupled and affected by each other, and the existing methods have poor simulation effects. And as floating photovoltaic systems gradually develop towards the ocean, pure floating photovoltaic arrays will be exposed to huge wind, wave and current loads, and the calculation results are often somewhat different from the actual situation, which affects the accuracy of the calculation results and limits the development of floating photovoltaic systems. Summary of the invention

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

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

[0007] A method for calculating the dynamic response of a pure floating photovoltaic array comprises the following steps:

[0008] S1. Determine the minimum repeating module of a pure floating photovoltaic array;

[0009] 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;

[0010] 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;

[0011] 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;

[0012] 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.

[0013] 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.

[0014] The step S2 comprises the following steps:

[0015] 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, where the initial value of k is 20, and 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 m minimum repeating modules in the direction of the short side of the array, thereby obtaining a small array composed of n×m minimum repeating modules;

[0016] 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;

[0017] 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;

[0018] 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.

[0019] The step S3 comprises the following steps:

[0020] S31, importing the simplified numerical equivalent three-dimensional digital model into finite element simulation software;

[0021] S32, setting corresponding environmental parameters according to the working conditions and environmental loads of the pure floating photovoltaic array;

[0022] 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.

[0023] Step S4 includes the following steps:

[0024] 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;

[0025] 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;

[0026] 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;

[0027] Wherein, step S41 comprises the following steps:

[0028] S411. Determine the connection structure and number of connections between numerical equivalent bodies according to the structure of the pure floating photovoltaic array;

[0029] S412, establishing a three-dimensional digital model of the connection structure;

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

[0031] 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;

[0032] 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.

[0033] The step S6 comprises the following steps:

[0034] 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;

[0035] 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;

[0036] 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 specific working conditions.

[0037] The connection structure, mooring system and photovoltaic module support structure are analyzed from the following perspectives:

[0038] S631, the strength analysis of the connection structure includes the following steps:

[0039] S6311, determining the location information of the connection structure to be analyzed;

[0040] 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;

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

[0042] S632, Mooring system analysis includes the following steps:

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

[0044] 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;

[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 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;

[0047] S633, PV module support structure analysis includes the following steps:

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

[0049] 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;

[0050] S6333, determining whether adjacent photovoltaic module support structures collide, if so, proceed to step S6334, if not, terminate the analysis;

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

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

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

[0054] 1. Based on the characteristics of pure floating photovoltaic arrays with simple structure and high repeatability, the present invention introduces the concepts of minimum repeating modules and numerical equivalents, simplifies the array composed of multiple minimum repeating modules into numerical equivalents similar to hydrodynamic performance, wind coefficient, and flow coefficient, and can quickly calculate large pure floating photovoltaic arrays to obtain the overall motion response of the array, thereby improving the calculation efficiency and reducing the calculation cost.

[0055] 2. The present invention improves the accuracy of the simplified model while ensuring the calculation speed; at the same time, the overall motion response of the array is used as the boundary condition, combined with the finite element analysis software of the structure to be analyzed, and the aspects of each structure to be optimized are calculated, which can help designers better understand and optimize the design of pure floating photovoltaic arrays, improve the quality and efficiency of the design, and then improve the performance of pure floating photovoltaic arrays, improve the reliability of the design and provide decision support.

[0056] 3. The present invention uses a simulation model to simulate the performance of a pure floating photovoltaic array under various working conditions in the early design stage, which helps to more accurately predict the hydrodynamic performance and structural reliability of the pure floating photovoltaic array, thereby reducing the number of design modifications and tests, and further ensuring that the obtained design scheme meets the preset use conditions and performance requirements, thereby enhancing the reliability of the design. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Shown is a flow chart of a method for calculating the dynamic response of a pure float type photovoltaic array of the present invention;

[0058] Figure 2 Shown is a schematic diagram of the overall structure of a pure floating photovoltaic array system;

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

[0060] Figure 4 Shown is a simplified schematic diagram 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. DETAILED DESCRIPTION

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

[0063] The flow chart of the dynamic response calculation method of the pure floating photovoltaic array of the present invention is as follows: Figure 1 As shown, the dynamic response calculation method of 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 pure floating photovoltaic array system structure.

[0065] The minimum repeating module has the following characteristics: repeated appearance in the photovoltaic array system, unified structural composition, unified structural function, unified material properties, and cannot be divided into smaller repeating structures.

[0066] Among them, the relevant parameters of pure floating photovoltaic arrays include the overall parameters of the photovoltaic array (including the main dimensions of the pure floating photovoltaic array, total displacement, mooring system layout plan, etc.), various floating 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 type, anchoring layout form, anchoring point water depth, etc.), photovoltaic support component parameters (including photovoltaic support component structure form, material parameters, fixing method, etc.), photovoltaic panel parameters (structure form, weight, moment of inertia, layout method, etc.).

[0067] The structural diagram of the pure floating photovoltaic array system of this embodiment is as follows: Figure 2 As shown, the structure of the pure floating photovoltaic array system includes a mooring system composed of multiple anchoring units, a floating system composed of multiple floating units, a photovoltaic system composed of several photovoltaic modules, and a connection system. Each anchoring unit includes a gravity anchor 11, a mooring cable 12, and a mooring cable-floating connection assembly 13. Each floating unit includes an equipment float 21, a main float 22, and an auxiliary float 23. Each photovoltaic module includes a photovoltaic panel 31 and a photovoltaic support assembly 32. The connection system includes several connecting bolts 41. The arrangement and connection form of the pure floating photovoltaic array are shown in FIG. Figure 3As shown, two main floating bodies 22 and two equipment floating bodies 21 are connected to form a whole by connecting bolts 41 through prefabricated holes of each floating body, and a photovoltaic module is fixed on the two equipment floating bodies 21 to form a minimum repeating module 51. The minimum repeating module 51 is as shown in FIG. Figure 3 As shown by the dashed line in the middle. Each minimum repeating module 51 is connected to each other by means of the auxiliary float 23 through the connecting bolts 41, and finally forms an array structure. The float hole position outside the array structure is 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 gravity anchor 11 is fixed at the other end of the mooring cable.

[0068] S2. According to the structural composition and minimum repeating module of the pure floating photovoltaic array, the numerical equivalent of the pure floating photovoltaic array is determined, and a three-dimensional digital model of the numerical equivalent is constructed using computer-aided design technology, and its structure is simplified.

[0069] Among them, the numerical equivalent is the component unit of the equivalent model obtained by reasonably dividing and simplifying the array during 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 direction of the long side of the array under the target working condition as the characteristic length λ, where the initial value of k is 20, and determine that the long side of the array is divided into n minimum repeating modules (n≥1). The method for determining n is based on the formula n=FLOOR(λ / a), where FLOOR() is a 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 into m minimum repeating modules, thereby obtaining 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 smallest repeating modules in the small array as a rigid connection. Under the premise of ensuring that the draft and waterplane area remain unchanged, a numerical model of the small array that is reasonably simplified in appearance, i.e., a numerical equivalent, is established.

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

[0075] like Figure 4 As shown, according to the minimum number and arrangement of repeated modules in the small matrix, the bolt connection 41 in a single small matrix is ​​equivalent to a rigid connection, that is, the single small matrix is ​​regarded as a rigid floating body. Under the premise of ensuring that the draft depth and waterplane area remain unchanged, the cross-sectional shape of the waterplane is simplified to reduce the complexity of the hydrodynamic performance calculation.

[0076] Specifically, the 3D modeling software SolidWorks was selected 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, the specific shape and structure of the numerical equivalent body, such as the cross-sectional shape of the waterplane surface and the array arrangement, were optimized to obtain a 3D digital model of the numerical equivalent body. In addition, a 3D digital model of a small array composed of minimum repeating modules was constructed for subsequent hydrodynamic analysis.

[0077] S23, respectively importing the three-dimensional digital model of the small array composed of the numerical equivalent body and the minimum repeating module into the hydrodynamic calculation software ANSYS AQWA to calculate its hydrodynamic performance under the target working condition;

[0078] Specifically, the three-dimensional digital models of the numerical equivalent body and the small array composed of the minimum repeating module were imported into the hydrodynamic analysis software ANSYS AQWA to establish simulation models. Among them, the numerical equivalent simulation model and the small array simulation model composed of the minimum repeating module have the same main scale, mooring form, wind wave and current environmental parameters, etc., that is, only the three-dimensional digital model is different. The simulation model is calculated to obtain the hydrodynamic performance of the first-order and second-order wave forces, wave resistance, stability, etc.

[0079] S24. Compare the obtained hydrodynamic performance. If the comparison result does not meet the expectation, return to step S21, set k=k+1, change the selection result method of the numerical equivalent or the simplification method of the numerical equivalent, until the comparison structure meets the expectation of the hydrodynamic performance, and obtain the simplified three-dimensional digital model of the numerical equivalent.

[0080] 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.

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

[0082] S31, importing the simplified numerical equivalent three-dimensional digital model into the finite element simulation software ABAQUS;

[0083] S32, setting corresponding environmental parameters according to the working conditions and environmental loads of the pure floating photovoltaic array;

[0084] S33. In the simulation software, based on the imported three-dimensional digital model of the numerical equivalent body and the set environmental parameters, an optimal numerical equivalent body simulation model is established to calculate the complete hydrodynamic performance, wind coefficient and flow coefficient of a single optimal numerical equivalent body model in the frequency domain.

[0085] 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.

[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 joint connection with three rotational degrees of freedom and different angular stiffness, including the following steps:

[0088] S411. Determine the connection structure and number of connections between numerical equivalent bodies according to the structure of the pure floating photovoltaic array;

[0089] S412, establishing a three-dimensional digital model of the connection structure;

[0090] S413, importing the three-dimensional digital model of the connection structure into finite element simulation software; in this embodiment, ABAQUS is used as the finite element simulation model;

[0091] S414. In the simulation software, based on the material properties assigned to the connection structure and the three-dimensional digital model, a simulation model is established, and the mechanical properties of a single connection structure are calculated;

[0092] Specifically, Figure 5 The figure shows a finite element simulation model of the connection structure established in ABAQUS, where 61 is a three-dimensional model of the auxiliary floating unit, 62 is a three-dimensional model of the main floating unit, and 63 is a three-dimensional model of the bolt connection unit; low-density polyethylene material is selected as the material parameters; and at the same time, the mesh density of the bolt connection unit is encrypted to improve the calculation accuracy.

[0093] S415, according to the mechanical properties of a single connection structure and the number and arrangement of the connection structures between the numerical equivalent bodies, determine the optimal arrangement direction and number of simplified connection methods between the numerical equivalent bodies. Figure 4 As shown, the connecting bolt 41 between the optimal numerical equivalent bodies is simplified to a spherical joint with three rotational degrees of freedom and different angular stiffness. This spherical joint has the same constraint effect on the relative motion between the numerical equivalent bodies as the original connection result.

[0094] S42, importing the hydrodynamic coefficient, wind force coefficient and flow force coefficient of the single optimal numerical equivalent body model into the simulation software OrcaFlex;

[0095] 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;

[0096] S5. Perform time domain numerical simulation on the numerical model of the overall size of the array under corresponding working conditions to obtain the motion response results of the array.

[0097] S6. Using the motion response results of the entire array as displacement boundary conditions, perform strength analysis on the connection structure, mooring system, and photovoltaic module support structure.

[0098] In this embodiment, step S6 includes the following steps:

[0099] 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;

[0100] 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;

[0101] 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 specific working conditions.

[0102] The connection structure, mooring system and photovoltaic module support structure are analyzed from the following perspectives:

[0103] S631, the strength analysis of the connection structure includes the following steps:

[0104] S6311, determining the location information of the connection structure to be analyzed;

[0105] 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;

[0106] Specifically, the displacement boundary condition refers to: the time-history results of the six-degree-of-freedom motion of the optimal numerical equivalent body on both sides of the connection, which is used to calculate the time-history results of the rotation angles on the three rotational degrees of freedom of the connecting spherical joint.

[0107] S6313. According to the simulation model in the simulation software of step S414 and the dynamic response results of the pure floating photovoltaic array, the boundary conditions and initial conditions of the simulation model are set, and the finite element software is run to calculate the stress and strain distribution of the connection structure.

[0108] S632, Mooring system analysis includes the following steps:

[0109] S6321. Determine the position information of the mooring system to be analyzed;

[0110] 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;

[0111] S6323. Establish a three-dimensional digital model of the mooring system; wherein the mooring system is composed of a plurality of anchoring units, each anchoring unit includes a gravity anchor 11, a mooring cable 12 and a mooring cable-floating body connection assembly 13.

[0112] S6324. In the simulation software OrcaFlex, a simulation model is established based on the three-dimensional digital model of the mooring system. The boundary conditions and initial conditions of the simulation model are set according to the dynamic response results of the pure floating photovoltaic array. After setting the environmental parameters, boundary conditions and initial conditions, the finite element calculation software is run to simulate and 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.

[0113] S633, PV module support structure analysis includes the following steps:

[0114] S6331. Determine the position information of the supporting structure of the photovoltaic module to be analyzed;

[0115] 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;

[0116] S6333, determining whether adjacent photovoltaic module support structures collide, if so, proceed to step S6334, if not, terminate the analysis;

[0117] S6334. Establish a three-dimensional digital model of the PV module support structure. In the simulation software, establish a simulation model based on the material properties and three-dimensional digital model of the PV module support structure. Set the boundary conditions and initial conditions of the simulation model according to the dynamic response results of the pure float type PV array. After setting the environmental parameters, boundary conditions and initial conditions, run the finite element calculation software simulation to obtain the damage results of the PV module support structure.

[0118] According to the characteristics of pure floating photovoltaic arrays, such as high modularity, huge number of modules, and high structural repeatability, the present invention proposes a method for calculating the dynamic response of pure floating photovoltaic arrays, introduces the concepts of minimum repeating modules and numerical equivalents, simplifies the array composed of multiple minimum repeating modules into numerical equivalents similar to hydrodynamic performance, wind force coefficient, and flow force coefficient, and can quickly calculate large pure floating photovoltaic arrays to obtain the motion response of the entire array, thereby 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, the motion response of the entire array is used as the boundary condition, combined with the finite element analysis software of the structure to be analyzed, the aspects to be optimized of each structure are calculated, so as to help designers better understand and optimize the design of pure floating photovoltaic arrays, improve the quality and efficiency of the design, and then improve the performance of pure floating photovoltaic arrays, improve the reliability of the design, and provide decision support.

[0119] The above is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection 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, where the initial value of k is 20, and 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 m minimum repeating modules in the direction of the short side of the array, thereby obtaining 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 specific working conditions.

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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