A photovoltaic frame and a method of assessing the strength of a photovoltaic frame

Abstract

The application provides a photovoltaic frame and a method for evaluating the strength of the photovoltaic frame, and belongs to the technical field of photovoltaic aluminum alloy frame assemblies. The photovoltaic frame comprises a long side piece, a short side piece, a corner piece, glass and U-shaped structural glue. The long side piece and the short side piece are connected into a rectangular frame through the corner piece. The glass is fixed in the notch of the rectangular frame through the U-shaped structural glue. The photovoltaic frame and the method for evaluating the strength of the photovoltaic frame can improve the connection reliability and fatigue resistance.

Description

Technical Field

[0001] This application belongs to the technical field of photovoltaic aluminum alloy frame components, and more specifically, it relates to a photovoltaic frame and a method for evaluating the strength of a photovoltaic frame. Background Technology

[0002] Photovoltaic modules typically consist of photovoltaic glass, solar cells, backsheets, and frames. The frames primarily serve a supporting and protective function and are connected to the brackets via mounting holes to ensure the structural integrity of the modules under external loads such as wind pressure and snow pressure.

[0003] Currently, the connection method between photovoltaic frames and glass is mostly to apply structural adhesive to the bottom of the frame groove, and the glass edge only contacts and bonds with one side of the adhesive layer. In this bonding method, the bonding area is limited, and the adhesive layer is prone to stress concentration when subjected to force. After long-term use or after being subjected to alternating loads, the adhesive layer is prone to peeling or cracking from the edge, resulting in loose glass, sealing failure, or even damage to the entire module. Summary of the Invention

[0004] This application provides a photovoltaic frame and a method for evaluating the strength of a photovoltaic frame, in order to solve the technical problems in the prior art that the strength of the frame itself cannot be accurately and individually tested, and that the cost and cycle of destructive testing of the entire module are high, thereby achieving the goal of rapid, low-cost and non-destructive evaluation of the strength of a photovoltaic frame.

[0005] To achieve the above objectives, the technical solutions provided in this application are as follows: In one aspect, a photovoltaic frame is provided, including: a long side piece, a short side piece, corner pieces, glass, and a U-shaped structural adhesive; The long and short side pieces are connected by corner pieces to form a rectangular frame; The glass is fixed to the groove of the rectangular frame using U-shaped structural adhesive.

[0006] Secondly, a method for evaluating the strength of a photovoltaic frame is provided, including: Construct a photovoltaic frame model based on the photovoltaic frame; Multiple standard loads were applied to the photovoltaic frame model in different directions, and finite element simulation was performed to obtain the corresponding deformation. The standard loads were obtained by calibrating the photovoltaic frame model. The mounting hole load is determined based on the standard load. The maximum stress value that the mounting hole can withstand is obtained by applying the mounting hole load force to the mounting hole in the photovoltaic frame model, and the maximum stress value is used as the target stress value. Based on the deformation and target stress values, the strength coefficient of the photovoltaic frame model is determined. The strength of the photovoltaic frame model is evaluated based on the strength coefficient value.

[0007] The beneficial effects of the technical solution provided in this application are as follows: Compared with related technologies, the photovoltaic frame and method for evaluating the strength of the photovoltaic frame provided in this embodiment use U-shaped structural adhesive to fix the glass in the groove of the rectangular frame. The cross-section of the U-shaped structural adhesive is U-shaped and wraps around and bonds the glass edge from the top, bottom and side of the glass. This embodiment significantly increases the bonding area and bonding strength, so that the glass and the frame form an integral stress structure, avoiding stress concentration and adhesive peeling risks, and improving connection reliability and fatigue resistance. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below.

[0009] Figure 1 This is a partial structural schematic diagram of the photovoltaic frame model provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the photovoltaic frame model provided in the embodiments of this application; Figure 3 A flowchart illustrating the method for evaluating the strength of a photovoltaic frame provided in an embodiment of this application; Figure 4 This is a simplified structural diagram of the photovoltaic frame model provided in the embodiments of this application; Figure 5 This is a schematic diagram of the long side structure of the photovoltaic frame model provided in the embodiments of this application; Figure 6 A schematic diagram of the glass structure provided in the embodiments of this application; Figure 7 This is a schematic diagram of a partial area of ​​the glass provided in an embodiment of this application.

[0010] Explanation of reference numerals in the attached drawings: 11-Long side piece, 12-Short side piece, 13-Corner piece, 14-Glass, 15-U-shaped structural adhesive, 16-Photovoltaic frame model bolt, 17-Crossbeam bracket, 21-A side surface, 22-Gutter edge, 23-B side surface, 24-Cavity side surface, 25-C side surface, 26-D side surface, 27-A cavity side surface, 31-First constraint area, 32-Second constraint area, 33-First load application area, 41-Indirect area between the glass and adhesive, 42-Load application area on the glass. Detailed Implementation

[0011] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.

[0012] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” and “the” used herein may also include the plural forms. It should be further understood that the terms “comprising” and “including” as used in embodiments of this application mean that the corresponding feature can be implemented as the presented feature, information, data, step, operation, element, and / or component, but do not exclude implementation as other features, information, data, step, operation, element, component, and / or combinations thereof supported by the art. It should be understood that when we say that an element is “connected” or “coupled” to another element, the one element can be directly connected or coupled to the other element, or it can mean that the one element and the other element establish a connection relationship through an intermediate element. Furthermore, “connected” or “coupled” as used herein can include wireless connection or wireless coupling. The term “and / or” as used herein indicates at least one of the items defined by the term; for example, “A and / or B” can be implemented as “A,” or as “B,” or as “A and B.” When describing multiple (two or more) items, if the relationship between the multiple items is not explicitly defined, the multiple items can refer to one, several or all of the multiple items. For example, the description of "parameter A includes A1, A2, A3" can be implemented as parameter A includes A1 or A2 or A3, or it can be implemented as parameter A includes at least two of the three items A1, A2 and A3.

[0013] This application provides a photovoltaic frame, such as... Figure 1 The diagram shown is a structural schematic of a photovoltaic frame model, which includes: a long side piece 11, a short side piece 12, a corner piece 13, glass 14, and a U-shaped structural adhesive 15. The long side piece 11 and the short side piece 12 are connected by the corner piece 13 to form a rectangular frame; The glass 14 is fixed to the groove of the rectangular frame by U-shaped structural adhesive 15.

[0014] In this embodiment, the corner piece 13 can be an L-shaped connector, which is inserted into the end cavities of the long side piece 11 and the short side piece 12 respectively, and fixed by screws or rivets to form a stable rectangular frame.

[0015] In this embodiment, the glass 14 is fixed to the groove of the rectangular frame by U-shaped structural adhesive 15. According to Figure 1 and Figure 2As shown, the inner side of the rectangular frame has a groove edge 22, and the U-shaped structural adhesive 15 is continuously arranged along the inner wall of the groove, forming a U-shaped cross-section. The edge of the glass 14 is inserted into the opening of the U-shaped structural adhesive 15, and the upper, lower, and side surfaces of the U-shaped structural adhesive 15 are tightly attached to the glass 14, thus firmly fixing the glass 14 to the frame through the adhesive action of the structural adhesive. The upper surface of the glass 14 is flush with the A-side surface 21 of the frame, and the lower part of the glass 14 is supported by the C-side surface 25 and the D-side surface 26.

[0016] In this embodiment, during actual assembly, the long side part 11 is also provided with multiple mounting holes (not shown in the figure) for connecting to the crossbeam bracket 17 via photovoltaic frame model bolts 16, thereby installing the entire photovoltaic module onto the support structure of the photovoltaic power station.

[0017] In one embodiment of this application, the long side member 11 is provided with a plurality of mounting holes for connecting to the crossbeam bracket 17 via photovoltaic frame model bolts 16; Mounting holes are also provided on the short side piece 12; U-shaped structural adhesive 15 is located between the glass 14 and the groove edge 22 of the rectangular frame, and is used to bond and fix the glass 14 to the long side piece 11 and the short side piece 12.

[0018] In this embodiment, see Figure 2 Side surface 21 is the upper surface of the frame, which is flush with the upper surface of the glass 14; side surface 23 is the outer vertical surface of the frame; side surface 25 is the inner bottom surface of the frame, which supports the glass 14; side surface 26 is the horizontal surface at the bottom of the frame; and cavity surface 27 is the inner vertical surface that forms the cavity.

[0019] The U-shaped structural adhesive 15 is continuously arranged along the groove of the rectangular frame, located between the glass 14 and the groove edge 22 of the rectangular frame. Specifically, as shown... Figure 2 As shown, the groove edge 22 is the inner sidewall of the frame, used to accommodate the glass 14 and the U-shaped structural adhesive 15. The U-shaped structural adhesive 15 has a U-shaped cross-section, with its opening facing the edge of the glass 14. The edge of the glass 14 is inserted into the U-shaped opening of the U-shaped structural adhesive 15, so that the structural adhesive wraps around and bonds the glass 14 from the top, bottom, and sides, thereby firmly fixing the glass 14 to the long side piece 11 and the short side piece 12. This U-shaped wrapping and bonding method can effectively transfer loads such as wind pressure and snow pressure, while also providing cushioning and sealing.

[0020] As can be seen from the above, this embodiment achieves reliable support and fixation of the glass plate through the photovoltaic frame structure described above, and at the same time, the photovoltaic module can be safely installed in the outdoor environment by connecting with the bracket through the mounting holes.

[0021] In the energy power generation industry, solar photovoltaic (PV) power generation has become a new type of power generation after thermal and hydropower. Solar PV modules collect solar energy through solar panels and convert it into electricity. To maximize solar energy collection, PV modules are mostly installed in open, sunny locations, but this also brings unfavorable environmental conditions such as strong winds and dust storms. Therefore, it is necessary to install sufficiently strong frame supports for the solar panels. Currently, the frame material is mostly extruded aluminum alloy profiles. After the solar PV panels and the frame are connected and combined with structural adhesive, they form a complete PV frame module. In related technologies, the methods for testing the strength of PV frame modules mainly rely on the strength test sequences specified in national standards. However, these tests are all overall strength tests, that is, tests are conducted on the complete module including the PV panel, structural adhesive, and frame. During the testing process, the frame is the direct provider of module strength, but the overall strength test is influenced by the PV panel and structural adhesive, including the contribution or interference of other factors during assembly. It is impossible to accurately and independently test the strength of the frame itself; furthermore, overall strength testing is a destructive test, and each test will damage the entire module, resulting in huge testing costs and long testing cycles.

[0022] To address the aforementioned technical problems, this application also provides a method for evaluating the strength of a photovoltaic frame. This method can be executed by an electronic device, such as... Figure 3 As shown, the method may include: S101: Construct a photovoltaic frame model based on the photovoltaic frame.

[0023] In this embodiment, the loads, normal loads, and load forces on the photovoltaic frame at the installation site are decomposed and simplified to obtain a photovoltaic frame model.

[0024] In one embodiment of this application, after establishing the photovoltaic frame model, the method further includes: The photovoltaic frame model is simplified according to a preset simplification method to obtain a simplified photovoltaic frame model.

[0025] In this embodiment, the preset simplification method can omit the glass 14 part, the U-shaped structural adhesive 15 part between the glass 14 and the frame, and the connection part between the long side and the short side of the photovoltaic frame model, thereby simplifying the original photovoltaic frame model (e.g., a complete photovoltaic rectangular frame) at a 1 / 4 scale to obtain the simplified photovoltaic frame model.

[0026] To improve computational efficiency, the original photovoltaic frame model can be simplified to 1 / 4 of the actual experimental model using a preset simplification method, resulting in a simplified photovoltaic frame model, such as... Figure 4 As shown, Figure 4 (a) shows a simplified photovoltaic frame model including glass 14 and U-shaped structural adhesive 15. Figure 4(b) represents a simplified photovoltaic frame model excluding glass 14 and U-shaped structural adhesive 15. In the simplified photovoltaic frame model, the force on the long side can be decomposed into a torsional moment perpendicular to its length direction, a force perpendicular to the first side surface (e.g., side surface B 23), and a force perpendicular to the second side surface (e.g., side surface C 25 corresponding to the long side), and the force on the short side can be decomposed into a force perpendicular to the third side surface (e.g., side surface C 24 corresponding to the short side).

[0027] As can be seen from the above, this embodiment can simplify the simulation of the entire photovoltaic module (including photovoltaic panel, U-shaped structural adhesive 15 and photovoltaic frame) to the simulation of the frame, and simplify the overall test to the test only for the frame, thereby improving the calculation efficiency and accuracy.

[0028] S102: Apply standard loads in multiple directions to the photovoltaic frame model, perform finite element simulation, and obtain the corresponding deformation.

[0029] In this embodiment, the standard load is obtained by calibrating the photovoltaic frame model.

[0030] In one embodiment of this application, before applying standard loads in multiple directions to the photovoltaic frame model, the method further includes: On the long side piece, the positions of its two ends are respectively set as the first constraint area and the second constraint area, and the center point of the long side piece is taken as the first origin. The first load application area of ​​the long side piece is determined according to the first origin and the preset application area range. On the short side piece, the positions of its two ends are respectively set as the third constraint region and the fourth constraint region. The center point of the short side piece is taken as the second origin. The second load application region of the short side piece is determined according to the second origin and the preset application region range. The first, second, third, and fourth constraint regions are used to simulate the support boundary conditions during the actual installation of the photovoltaic frame model.

[0031] In this embodiment, a simplified model for applying loads individually is established using finite element simulation software. First, the geometric models corresponding to the long and short side components in the photovoltaic frame model are obtained. This embodiment uses the long side component as an example; its geometric model has a length of 1000mm. Figure 5The long side component is imported into finite element simulation software (e.g., ANSYS), and the geometric model is edited. In this embodiment, the support boundary conditions during the actual installation of the photovoltaic frame are simulated (e.g., fixed connection to the crossbeam bracket via bolts or clamps). A first constraint region 31 and a second constraint region 32 are respectively set at both ends of the long side component. Specifically, the first constraint region 31 and the second constraint region 32 are regions extending inward from the end faces of both ends of the long side component by a preset constraint width (in this embodiment, the preset constraint width is 20mm). Fixed constraints are applied to the above regions to restrict all degrees of freedom.

[0032] In this embodiment, the geometric center point of the long-side component is taken as the first origin. Using this first origin as the center of symmetry, the first load application area 33 is determined according to a preset application range. In this embodiment, the preset application range refers to the area defined by extending a preset length (e.g., 50mm) from the first origin to both sides, i.e., the middle area with a total length of 100mm. This load application area is used to simulate the equivalent concentrated action location of uniformly distributed loads such as wind pressure and snow pressure, to avoid local stress singularities caused by excessive concentration of load application points, and to avoid the boundary effect influence of the constrained areas at both ends.

[0033] In this embodiment, the short-side component is treated in the same way as the long-side component. In this embodiment, the geometric model length of the short-side component can be 600mm. A third constraint region and a fourth constraint region, each 20mm wide, are defined at both ends of the short-side component, and the same fixed constraints are applied. Using its geometric center point as the second origin, a second load application region with a total length of 100mm is defined by extending 50mm to each side.

[0034] In this embodiment, the constraint region is also used to restrict the movement of the border in the model, causing it to deform when a load is applied.

[0035] As can be seen from the above, this embodiment sets the two ends of the long side component and the two ends of the short side component as constraint regions, avoiding simulation distortion caused by simplified point constraints or full-edge constraints, and significantly improving the reliability and accuracy of simulation results. This embodiment limits the constraint region and load application region to a local area of ​​the photovoltaic frame model, which can improve simulation calculation efficiency while ensuring calculation accuracy.

[0036] In one embodiment of this application, standard loads in multiple directions are applied to the photovoltaic frame model, and finite element simulation is performed to obtain the corresponding deformation, including: The first simulation is performed on the long side of the photovoltaic frame model according to the standard load to obtain the corresponding deformation; the first simulation points to the standard load applied to the photovoltaic frame model in a first preset direction; A second simulation is performed on the short side of the photovoltaic frame model based on the standard load to obtain the corresponding deformation; the second simulation points to the standard load applied to the photovoltaic frame model in a second preset direction.

[0037] In this embodiment, the first preset direction includes the length direction of the long side component, the direction perpendicular to the first side surface (B side surface 23), and the direction perpendicular to the second side surface (C side surface 25). The second preset direction includes the direction perpendicular to the third side surface (C cavity side surface 24).

[0038] In this embodiment, a torsional torque perpendicular to the length direction is applied to the long side component. For example, the initial torque is set to 15 N·m and applied to the first load application area 33 of the long side component (i.e., the range extending 50 mm to both sides from the center point). Through finite element simulation calculation, the deformation of the center position of the long side component under the action of this torque is extracted and denoted as the first deformation P1.

[0039] In this embodiment, a force perpendicular to its first side surface (side surface 23) is applied to the long side component. For example, the magnitude of the force is set to 30 N, the direction is perpendicular to side surface 23, and it is uniformly applied to the first load application area 33 of the long side component. Through simulation calculation, the deformation at the center position of the long side component is extracted and denoted as the second deformation P2.

[0040] In this embodiment, a force perpendicular to its second side surface (C side surface 25) is applied to the long side component. For example, the magnitude of the force is set to 30 N, the direction is perpendicular to C side surface 25, and it is uniformly applied to the first load application area 33 of the long side component. Through simulation calculation, the deformation at the center position of the long side component is extracted and denoted as the third deformation P3.

[0041] In this embodiment, a force perpendicular to the third side surface (C-cavity side surface 24) of the short side component is applied. For example, the magnitude of the force is set to 30 N, the direction is perpendicular to the C-cavity side surface 24 of the short side component, and it is uniformly applied to the second load application area of ​​the short side component (i.e., the range extending 50 mm to both sides from the center point of the short side component, the second load application area is not shown in the figure). Through finite element simulation calculation, the deformation at the center position of the short side component is extracted and denoted as the fourth deformation P4.

[0042] As can be seen from the above, this embodiment improves the accuracy of the evaluation by performing independent simulations on the long side component and the short side component separately and applying their respective preset directional loads, thus avoiding mutual coupling interference caused by mixed simulations.

[0043] In one embodiment of this application, before applying standard loads in multiple directions to the photovoltaic frame model, the standard loads are calibrated, wherein calibrating the standard loads includes: An adjustable load is applied to the photovoltaic frame model, and the fifth deformation at the center position of the photovoltaic frame model under the adjustable load is obtained; Initial independent loads are applied in each direction of the photovoltaic frame model to obtain the initial deformation of the photovoltaic frame model in each direction; According to the preset decomposition rules, the fifth deformation quantity is decomposed into sub-deformation quantities corresponding to each initial deformation quantity; For each initial deformation and its corresponding sub-deformation, the error between the initial deformation and the sub-deformation is obtained. For initial independent loads whose error is within a preset error range, the initial independent load is used as the standard load. For initial independent loads whose error is outside the preset error range, the initial independent load is adjusted until the error is within the preset error range.

[0044] In this embodiment, an adjustable total load (e.g., an initial surface pressure of 500 Pa, perpendicular to the glass) is applied to the load application area of ​​the photovoltaic frame model. The deformation at the center of the photovoltaic frame model (i.e., the center point of the glass) is extracted through finite element simulation and denoted as the fifth deformation (unit: mm). This fifth deformation reflects the comprehensive response of the photovoltaic frame model under a given total load.

[0045] Obtain the initial independent loads of the photovoltaic frame model in multiple directions, such as the torsional moment on the long side (initial value 15 N·m), the surface force on the long side B (initial value 30 N), the surface force on the long side C (initial value 30 N), and the surface force on the short side C (initial value 30 N). The initial independent loads in this embodiment can be set based on experience or theoretical estimation.

[0046] The aforementioned initial independent loads were applied individually to the photovoltaic frame model. Through finite element simulation calculations, the initial deformation of the center position of the photovoltaic frame model under the individual action of loads in each direction was obtained, including: the first initial deformation corresponding to the torsional moment of the long side, the second initial deformation corresponding to the force 23 on the B side surface, the third initial deformation corresponding to the force 25 on the C side surface, and the fourth initial deformation corresponding to the force 24 on the C cavity side surface of the short side.

[0047] See Figure 6 This is a schematic diagram of the glass structure in this embodiment. In this embodiment, the area 41 between the glass and the adhesive and the load application area 42 are defined on the glass. In this embodiment, the distance between the rectangular edge and the edge of the glass is set to 1.5 cm. Figure 7The diagram shown is a partial view of the glass in this embodiment. In this embodiment, the fifth deformation is decomposed into sub-deformation quantities corresponding to each initial deformation quantity according to a preset decomposition rule. The preset decomposition rule in this embodiment can decompose the fifth deformation quantity based on the proportion of each initial deformation quantity in the total initial deformation quantity, obtaining the first sub-deformation quantity corresponding to the first initial deformation quantity, the second sub-deformation quantity corresponding to the second initial deformation quantity, the third sub-deformation quantity corresponding to the third initial deformation quantity, and the fourth sub-deformation quantity corresponding to the fourth initial deformation quantity.

[0048] This embodiment calculates the error between each initial deformation and its corresponding sub-deformation. For example, taking the first initial deformation and the first sub-deformation corresponding to the long-side torsional moment direction as an example, the error between the first initial deformation and the first sub-deformation is calculated. If the error is within a preset error range (e.g., ±5%), the initial independent load in that direction (i.e., the long-side torsional moment of 15 N·m) is used as the standard load in that direction; otherwise, the magnitude of the initial independent load is adjusted until the error is within the preset error range. The adjustment method in this embodiment can be as follows: if the first initial deformation is greater than the first sub-deformation, it indicates that the actual deformation under the load in that direction is too large and the model stiffness is too small, and the independent load in that direction should be appropriately reduced; if the first initial deformation is less than the first sub-deformation, it indicates that the actual deformation under the load in that direction is too small and the model stiffness is too large, and the independent load in that direction should be appropriately increased.

[0049] In this embodiment, after adjusting the first initial independent load, the adjusted initial deformation under the adjusted independent load in that direction is recalculated, the error between the adjusted initial deformation and the first sub-deformation is obtained, and the error is compared with the preset error range. This process is repeated until the error meets the requirements.

[0050] For other directions (long side B surface 23 force, long side C surface 25 force, short side C cavity surface 24 force), the above calibration process is performed independently.

[0051] In this embodiment, after the error in each direction is within the preset error range, the adjusted independent loads are recorded, and each independent load is used as the test condition (standard load) to determine the strength of the new frame structure.

[0052] In this embodiment, when evaluating a new photovoltaic frame model, the above-mentioned standard load force can be applied to the new model to be evaluated, the corresponding strength coefficient value can be calculated, and it can be compared with a preset strength threshold to obtain the evaluation conclusion.

[0053] As can be seen from the above, this embodiment achieves the best balance between computational efficiency and accuracy by calibrating the standard load, thus enabling rapid evaluation.

[0054] S103: Determine the mounting hole load based on the standard load. Apply the mounting hole load force to the mounting hole in the photovoltaic frame model to obtain the maximum stress value that the mounting hole can withstand, and use the maximum stress value as the target stress value.

[0055] In one embodiment of this application, the mounting hole load is determined according to a standard load. The maximum stress value that the mounting hole can withstand is obtained by applying the mounting hole load force to the mounting hole in the photovoltaic frame model, and the maximum stress value is used as the target stress value. This includes: Select a simulated mounting hole on the long side component as the target mounting hole; Based on the standard load, the equivalent normal force borne by the target mounting hole is determined by the static equilibrium method, and the equivalent normal force is used as the mounting hole load. Apply a mounting hole load to the target mounting hole and calculate the maximum equivalent stress value in the edge region of the target mounting hole using finite element simulation. Use the maximum equivalent stress value as the target stress value.

[0056] In this embodiment, a representative simulated mounting hole is selected on the long side component as the target mounting hole. For example, a mounting hole near the center of the long side component or the one with the greatest stress can be selected to obtain the most unfavorable stress result.

[0057] This embodiment calculates the equivalent normal force borne by the target mounting hole location using a static equilibrium method based on the standard loads obtained above in multiple directions (e.g., torque along the length of the long side, force 23 on the B-side surface corresponding to the long side, force 25 on the C-side surface corresponding to the long side, and force 24 on the C-side surface corresponding to the short side). The static equilibrium method treats the entire photovoltaic frame model as a rigid body under force equilibrium. Based on the magnitude and location of the standard loads and the distribution of the mounting holes, the load borne by each mounting hole is determined using moment balance and force balance equations. The equivalent normal force refers to the transverse force (simulating shearing) perpendicular to the mounting hole axis or the tensile force (simulating tension) along the axial direction that the target mounting hole experiences when bolted. In this embodiment, this equivalent normal force is used as the mounting hole load applied to the target mounting hole.

[0058] In this embodiment, a mounting hole load is applied to the target mounting hole in finite element simulation software, while other degrees of freedom of the surrounding frame are constrained. Through finite element simulation calculation, the maximum equivalent stress value of the edge region of the target mounting hole (usually the junction of the hole wall and the frame surface, where stress concentration is prone to occur) is extracted, and this maximum equivalent stress value is used as the target stress value.

[0059] As can be seen from the above, this embodiment directly obtains the maximum equivalent stress value of the mounting hole edge region through finite element simulation, which can quantitatively assess the strength reserve of this weak link and make up for the shortcomings of only focusing on the overall deformation. This embodiment determines the equivalent normal force at the location of the target mounting hole from the calibrated standard load, and establishes a clear mechanical mapping relationship between the overall macroscopic frame stress and the local connection point load, avoiding the arbitrariness of empirical estimation or arbitrary value selection, and improving the accuracy of simulation results.

[0060] S104: Determine the strength coefficient value of the photovoltaic frame model based on the deformation and target stress values.

[0061] In one embodiment of this application, the deformation includes a first deformation, a second deformation, a third deformation, and a fourth deformation; wherein, the first deformation refers to the deformation at the center position corresponding to the direction of the torsional moment applied perpendicular to the length direction of the long side member, the second deformation refers to the deformation at the center position corresponding to the direction of the force applied perpendicular to the first side surface of the long side member, the third deformation refers to the deformation at the center position corresponding to the direction of the force applied perpendicular to the second side surface of the long side member, and the fourth deformation refers to the deformation at the center position corresponding to the direction of the force applied perpendicular to the third side surface of the short side member. Based on the deformation and target stress values, the strength coefficient values ​​of the photovoltaic frame model are determined, including: Based on the deformation, target stress value, and penalty function, and using the strength coefficient calculation formula, the strength coefficient value of the photovoltaic frame model is calculated; the penalty function is used to characterize the penalty effect on the strength coefficient when the target stress value exceeds a preset threshold. The formula for calculating the strength coefficient is as follows: ,in, This represents the intensity coefficient value of the photovoltaic frame model. Indicates the first deformation amount. This indicates the second deformation amount. Indicates the third deformation amount. Indicates the fourth deformation amount. This indicates the weight corresponding to the first deformation. This indicates the weight corresponding to the second deformation. This indicates the weight corresponding to the third deformation. This indicates the weight corresponding to the fourth deformation. Represents the penalty function. This represents the target stress value.

[0062] This embodiment uses an equivalent load and sets four deformation quantities. The first deformation quantity refers to the deformation at the center of the long side component when a torsional moment perpendicular to its length direction (15 N·m in this embodiment) is applied to the long side component (unit: mm). The second deformation quantity refers to the deformation at the center of the long side component when a force perpendicular to its first side surface (i.e., side surface 23, B) (30 N in this embodiment) is applied to the long side component. The third deformation quantity refers to the deformation at the center of the long side component when a force perpendicular to its second side surface (i.e., side surface 25 corresponding to the long side, C) (30 N in this embodiment) is applied to the long side component. The fourth deformation quantity refers to the deformation at the center of the short side component when a force perpendicular to its third side surface (i.e., side surface 24 corresponding to the short side, C) (30 N in this embodiment) is applied to the short side component. In this embodiment, each deformation quantity is a fixed value, used to characterize the response of the frame center position under equivalent loads in different directions.

[0063] It should be noted that the number of deformation quantities is directly related to the equivalent accuracy: if too few deformation quantities are used, it will be difficult to fully reflect the multi-directional coupling effect of the actual load, resulting in a significant increase in the equivalent error; in this embodiment, by setting four deformation quantities, the equivalent error is controlled within an acceptable range while ensuring calculation efficiency.

[0064] This embodiment obtains the deformation in four directions ( , , as well as After determining the target stress value at the edge of the mounting hole, the strength coefficient value of the photovoltaic frame model is further determined using the strength coefficient value calculation formula.

[0065] In the formula for calculating the strength coefficient, a larger strength coefficient value Y indicates poorer strength, while a smaller value Y indicates better strength. The weights corresponding to the first, second, and third deformation amounts, as well as the weight corresponding to the fourth deformation amount, can be pre-set based on the degree of influence of loads in each direction on the overall strength of the frame. For example, if the torsional stiffness of the long side has a significant impact on the stability of the frame, it can be assigned a certain weight. Higher weights. In this embodiment, all four weights are set to 0.25, meaning they are equally important.

[0066] The penalty function in this embodiment Target stress value at the edge of the mounting hole When the material is close to or exceeds its limits, the strength coefficient value is reduced to reflect the reduction in the overall strength of the frame due to the risk of tearing of the mounting holes.

[0067] In this embodiment, the tensile strength limit of the frame material (e.g., aluminum alloy 6063-T5) can be set to 280 MPa. When the target stress value is much less than 280 MPa, the penalty function value is small (it can be designed to be close to 0); when the target stress value is close to 280 MPa, the penalty function value increases. At this time, it is necessary to reduce the strength coefficient value to indicate insufficient strength reserve.

[0068] S105: Perform strength assessment on the photovoltaic frame model based on the strength coefficient value.

[0069] In one embodiment of this application, evaluating a photovoltaic frame model based on an intensity coefficient value includes: If the strength coefficient value is less than or equal to the preset strength threshold, the strength of the photovoltaic frame model is deemed qualified. If the strength coefficient value is greater than the preset strength threshold, the strength of the photovoltaic frame model is deemed unqualified.

[0070] In this embodiment, the preset strength threshold refers to a pre-calibrated empirical value or design standard value, which is used to distinguish whether the strength of the photovoltaic frame meets the usage requirements.

[0071] In this embodiment, if the strength coefficient value is less than or equal to the preset strength threshold (for example, the preset strength threshold is 10), the strength of the photovoltaic frame model is determined to be qualified, indicating that under the action of standard load, the overall deformation of the frame and the local stress of the mounting hole are within the design allowable range, and can meet the strength and stiffness requirements under normal use conditions.

[0072] If the strength coefficient value is greater than the preset strength threshold, the strength of the photovoltaic frame model is deemed unqualified. This indicates that the deformation of the photovoltaic frame in one or more directions is too large, or the stress at the edge of the mounting hole is close to or exceeds the material limit. The photovoltaic frame may undergo excessive deformation or even damage in actual service, and optimization design is required.

[0073] In this embodiment, after the evaluation is completed, the evaluation results are output in a visual form. For example, the simulation software interface displays "Strength qualified (Y=8.5≤10)" or "Strength unqualified (Y=12.3>10)" and generates an evaluation report. This evaluation report includes each deformation (first to fourth deformation), target stress value, and strength coefficient value, for designers to refer to and improve.

[0074] As can be seen from the above, this embodiment can automatically complete the evaluation and judgment and output the results by setting a unified preset strength threshold, without the need for manual intervention. The evaluation steps in this embodiment are based on simulation calculation results, without the need to make physical samples or conduct destructive mechanical load tests. Compared with traditional national standard tests, the entire process from modeling to judgment can be completed within a few hours, significantly reducing testing costs and time investment.

[0075] This embodiment simplifies the simulation of the entire photovoltaic frame model (including the photovoltaic panel, adhesive, and frame) to the simulation of the module frame. Simultaneously, the experiment is simplified from a complete test to a test focusing solely on the frame. By simulating the forces experienced by the frame during use and performing discrete point verification on the simulation results using only the frame, the accuracy of the simulation model is ensured. This embodiment also accurately recreates the post-installation operating conditions of the module by analyzing the working conditions of the module installation area and disassembling the module strength test. The deformation of the frame allows for accurate evaluation of its strength, shortening the cycle time and reducing costs. This provides direction for optimizing the photovoltaic frame structure, allowing for multi-faceted evaluation of the frame's strength under operating conditions, and enabling targeted optimization of the frame to achieve lean and customized design, while achieving an extremely lightweight structure.

[0076] As can be seen from the above, this embodiment can replace destructive testing with finite element simulation, which can significantly reduce testing costs and shorten the cycle. This embodiment obtains the deformation at the center of the frame by applying multi-directional standard loads and combines the simulation results of the tear strength of the mounting holes to comprehensively determine the strength coefficient value of the photovoltaic frame model, thus overcoming the shortcomings of existing technologies that cannot accurately and independently test the strength of the frame itself.

[0077] The above are only optional implementation methods for some implementation scenarios of this application. It should be noted that for those skilled in the art, other similar implementation methods based on the technical concept of this application without departing from the technical concept of this application also fall within the protection scope of the embodiments of this application.

Claims

1. A photovoltaic frame, characterized in that, include: Long-side components, short-side components, corner components, glass, and U-shaped structural adhesive; The long side piece and the short side piece are connected to form a rectangular frame via the corner piece; The glass is fixed to the groove of the rectangular frame by the U-shaped structural adhesive.

2. The photovoltaic frame as described in claim 1, characterized in that, The photovoltaic frame also includes a slotted edge. The long side component is provided with multiple mounting holes for connecting to the crossbeam bracket by bolts; The short side component is also provided with mounting holes; The U-shaped structural adhesive is located between the glass and the groove edge of the rectangular frame, and is used to bond and fix the glass to the long side piece and the short side piece.

3. A method for evaluating the strength of a photovoltaic frame, characterized in that, The photovoltaic frame is as described in any one of claims 1-2; the method includes: A photovoltaic frame model is constructed based on the aforementioned photovoltaic frame. Multiple standard loads in various directions were applied to the photovoltaic frame model, and finite element simulation was performed to obtain the corresponding deformation. The standard loads were obtained by calibrating the photovoltaic frame model. The mounting hole load is determined according to the standard load. The mounting hole load is applied to the mounting hole in the photovoltaic frame model to obtain the maximum stress value that the mounting hole can withstand. The maximum stress value is used as the target stress value. The strength coefficient value of the photovoltaic frame model is determined based on the deformation amount and the target stress value. The strength of the photovoltaic frame model is evaluated based on the strength coefficient value.

4. The method for evaluating the strength of a photovoltaic frame as described in claim 3, characterized in that, The method further includes: The photovoltaic frame model is simplified according to a preset simplification method to obtain a simplified photovoltaic frame model.

5. The method for evaluating the strength of a photovoltaic frame as described in claim 3, characterized in that, The photovoltaic frame model is subjected to standard loads in multiple directions, and finite element simulation is performed to obtain the corresponding deformation, including: The long side of the photovoltaic frame model is subjected to a first simulation based on the standard load to obtain the corresponding deformation; the first simulation applies a standard load in a first preset direction to the photovoltaic frame model; A second simulation is performed on the short side of the photovoltaic frame model based on the standard load to obtain the corresponding deformation; the second simulation applies a standard load in a second preset direction to the photovoltaic frame model.

6. The method for evaluating the strength of a photovoltaic frame as described in claim 5, characterized in that, The deformation includes a first deformation, a second deformation, a third deformation, and a fourth deformation; wherein, the first deformation refers to the deformation at the center position corresponding to the direction of the torsional moment applied perpendicular to the length direction of the long side piece, the second deformation refers to the deformation at the center position corresponding to the direction of the force applied perpendicular to the first side surface of the long side piece, the third deformation refers to the deformation at the center position corresponding to the direction of the force applied perpendicular to the second side surface of the long side piece, and the fourth deformation refers to the deformation at the center position corresponding to the direction of the force applied perpendicular to the third side surface of the short side piece. Determining the strength coefficient value of the photovoltaic frame model based on each of the deformation amounts and the target stress value includes: Based on the aforementioned deformation amounts, the target stress value, and the penalty function, and using the strength coefficient value calculation formula, the strength coefficient value of the photovoltaic frame model is calculated; the penalty function is used to characterize the penalty effect on the strength coefficient when the target stress value exceeds a preset threshold. The formula for calculating the strength coefficient is as follows: ,in, This represents the intensity coefficient value of the photovoltaic frame model. Indicates the first deformation amount. This indicates the second deformation amount. Indicates the third deformation amount. Indicates the fourth deformation amount. This indicates the weight corresponding to the first deformation. This indicates the weight corresponding to the second deformation. This indicates the weight corresponding to the third deformation. This indicates the weight corresponding to the fourth deformation. Represents the penalty function. This represents the target stress value.

7. The method for evaluating the strength of a photovoltaic frame as described in claim 3, characterized in that, Before applying standard loads in multiple directions to the photovoltaic frame model, the following steps are also included: On the long side piece, the positions of its two ends are respectively set as the first constraint region and the second constraint region, and the center point of the long side piece is taken as the first origin. The first load application region of the long side piece is determined according to the first origin and the preset application region range. On the short side piece, the positions of its two ends are respectively set as the third constraint region and the fourth constraint region. The center point of the short side piece is taken as the second origin. The second load application region of the short side piece is determined according to the second origin and the preset application region range. The first constraint region, the second constraint region, the third constraint region, and the fourth constraint region are used to simulate the support boundary conditions when the photovoltaic frame model is actually installed.

8. The method for evaluating the strength of a photovoltaic frame as described in claim 3, characterized in that, The step of evaluating the strength of the photovoltaic frame model based on the strength coefficient value includes: If the strength coefficient value is less than or equal to the preset strength threshold, the strength of the photovoltaic frame model is deemed to be qualified. If the strength coefficient value is greater than the preset strength threshold, the strength of the photovoltaic frame model is determined to be unqualified.

9. The method for evaluating the strength of a photovoltaic frame as described in claim 3, characterized in that, Before applying standard loads in multiple directions to the photovoltaic frame model, the following steps are also included: An adjustable load is applied to the photovoltaic frame model to obtain the fifth deformation at the center position of the photovoltaic frame model under the adjustable load; Initial independent loads are applied in each direction of the photovoltaic frame model to obtain the initial deformation of the photovoltaic frame model in each direction; According to the preset decomposition rules, the fifth deformation amount is decomposed into sub-deformation amounts corresponding to each of the initial deformation amounts; For each initial deformation and its corresponding sub-deformation, the error between the initial deformation and the sub-deformation is obtained. For initial independent loads whose error is within a preset error range, the initial independent load is used as the standard load. For initial independent loads whose error is outside the preset error range, the initial independent load is adjusted until the error is within the preset error range.

10. The method for evaluating the strength of a photovoltaic frame as described in claim 3, characterized in that, The step of determining the mounting hole load based on the standard load, and applying the mounting hole load force to the mounting holes in the photovoltaic frame model to obtain the maximum stress value that the mounting holes can withstand, and using the maximum stress value as the target stress value, includes: Select a simulated mounting hole on the long side component as the target mounting hole; Based on the standard load, the equivalent normal force borne at the location of the target mounting hole is determined by the static balance method, and the equivalent normal force is used as the mounting hole load. The mounting hole load is applied to the target mounting hole, and the maximum equivalent stress value of the edge region of the target mounting hole is calculated by finite element simulation. The maximum equivalent stress value is used as the target stress value.

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