Anti-subfissure method for photovoltaic module

Abstract

The invention provides an anti-subfissure method for a photovoltaic module, and relates to the technical field of photovoltaic power generation. According to the method, the hidden cracks on the to-be-detected photovoltaic module are classified, the probability of occurrence of different hidden crack types is determined, the wind pressure partition is carried out on the photovoltaic array, the multiple wind pressure partitions are determined, and finally, different anti-hidden-crack protection measures are adopted according to the probability of occurrence of different hidden crack types and different wind pressure partitions. Therefore, the anti-subfissure protection can be carried out on the photovoltaic module more comprehensively, and the escape of risk factors causing subfissure is avoided.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic power generation technology, and in particular to a method for preventing hidden cracks in photovoltaic modules. Background Art

[0002] With the continuous development of large-scale ground photovoltaic power generation projects, flat and open ground scenes are becoming less and less, and there are more and more application scenes such as hillsides, swamps, and water treatment plants. The small-span dense column-type purlin photovoltaic brackets suitable for the aforementioned application scenes are not suitable for the latter scenes, and large-span flexible brackets are gradually being promoted.

[0003] The long-span flexible bracket introduces steel cables as the main support, which increases the span between columns by 5-10 times from 6 meters of the purlin type to more than 30 meters, greatly improving the adaptability to photovoltaic installation scenarios. However, as the project progresses, it is found that the long-span flexible bracket has a significant change in the support strength and rigidity of photovoltaic modules, resulting in an increased risk of hidden cracks in the modules.

[0004] Therefore, there is an urgent need for a method for preventing hidden cracks in photovoltaic modules. Summary of the invention

[0005] In view of the above problems, an embodiment of the present application provides a method for preventing hidden cracks in a photovoltaic module, so as to overcome the above problems or at least partially solve the above problems.

[0006] In a first aspect of an embodiment of the present application, a method for resisting hidden cracks of a photovoltaic module is provided, the method comprising:

[0007] Performing a mechanical load test on the photovoltaic module to be tested, classifying the hidden cracks occurring on the photovoltaic module to be tested, and determining the corresponding relationship between the mechanical load applied to the photovoltaic module to be tested and the classified hidden crack types;

[0008] Obtaining a basic load at a current project location, and determining a probability of occurrence of at least one type of hidden crack according to the basic load;

[0009] Partitioning a standard photovoltaic array composed of a plurality of photovoltaic modules to be tested according to a wind pressure attenuation ratio to obtain a plurality of wind pressure partitions;

[0010] According to the probability of occurrence of the at least one type of hidden cracks and / or the multiple wind pressure zones, the photovoltaic assembly to be tested is protected against hidden cracks.

[0011] Optionally, the performing of a mechanical load test on the photovoltaic assembly to be tested and classifying hidden cracks occurring on the photovoltaic assembly to be tested includes:

[0012] Performing an initial EL test on the photovoltaic module to be tested to determine that no hidden cracks occur in the photovoltaic module to be tested;

[0013] Applying a mechanical load to the photovoltaic module to be tested without any hidden cracks, and observing the hidden cracks of the photovoltaic module to be tested through a post-test EL test;

[0014] The hidden cracks on the photovoltaic assembly to be tested are classified according to the areas where the hidden cracks are located.

[0015] Optionally, determining the correspondence between the mechanical load applied to the photovoltaic assembly to be tested and the classified hidden crack type includes:

[0016] When performing the mechanical load test on the photovoltaic assembly to be tested, monitoring the attenuation of the current of the photovoltaic assembly to be tested;

[0017] Each time the attenuation value increases by a preset step length, recording the type of hidden cracks occurring on the photovoltaic assembly to be tested and the mechanical load corresponding to the type of hidden cracks;

[0018] When the attenuation reaches the preset attenuation, the corresponding relationship between each of the hidden crack types and the mechanical load is determined, and the mechanical load test includes a front mechanical static load test, a back mechanical static load test or a mechanical dynamic load test.

[0019] Optionally, the basic load data includes: wind and snow load, gravity load and earthquake load; the obtaining of the basic load at the current project location and determining the probability of occurrence of at least one type of hidden crack according to the basic load includes:

[0020] Obtaining comprehensive geographic information of the project location, as well as the bracket height and component inclination angle of the photovoltaic component to be tested;

[0021] Based on the comprehensive geographic information, determining weight coefficients corresponding to the wind and snow load, the gravity load, and the earthquake load;

[0022] Based on the weight coefficient, weighted sum of the wind and snow load, the gravity load and the earthquake load is performed to obtain a basic comprehensive load;

[0023] Determining the shape factor, gust factor and height factor of the photovoltaic module to be tested according to the bracket height and the module inclination angle;

[0024] Determining a comprehensive load corresponding to the basic comprehensive load according to the shape coefficient, the gust coefficient and the height coefficient;

[0025] The probability of occurrence of at least one of the hidden crack types is determined according to the corresponding relationship between the comprehensive load and the mechanical load applied to the photovoltaic assembly to be tested and at least one of the hidden crack types.

[0026] Optionally, the hidden crack types include: local deformation and hidden cracks at four-point support parts, overall concave deformation and hidden cracks at the middle part of the component, hidden cracks in the area connecting two support points parallel to the short side, and sporadic hidden cracks; and the anti-hidden crack protection of the photovoltaic component to be tested based on the probability of occurrence of at least one hidden crack type includes:

[0027] In view of the local deformation and cracking of the four-point support parts, anti-crack protection measures are taken to increase the area of ​​the lower support surface of the photovoltaic module to be tested;

[0028] In view of the overall concave deformation and hidden cracks in the middle part of the module, an anti-hidden crack protection measure is taken to add auxiliary support to the middle area of ​​the photovoltaic module to be tested;

[0029] In view of the hidden cracks in the area connecting the two supporting points parallel to the short side, a protective measure against hidden cracks is adopted, in which the lower supporting point of the steel strand and the photovoltaic module to be tested is changed to a multi-point support;

[0030] To address the sporadic hidden cracks, anti-hidden crack protection measures are taken such as adding damping and elastic buffering in the middle of the steel strand span, or adding elastic pads at the contact point between the photovoltaic module to be tested and the steel strand.

[0031] Optionally, the standard photovoltaic array composed of the plurality of photovoltaic modules to be tested is partitioned according to the attenuation ratio of wind pressure to obtain a plurality of wind pressure partitions, including:

[0032] Performing a digital simulation wind tunnel test on a standard photovoltaic array composed of a plurality of photovoltaic modules to be tested;

[0033] Based on the digital simulation wind tunnel test, determining the wind pressure attenuation ratios of different areas of the standard photovoltaic array;

[0034] The standard photovoltaic array is divided into wind pressure zones according to the wind pressure attenuation ratio.

[0035] Optionally, the step of performing anti-hidden crack protection on the photovoltaic assembly to be tested for the plurality of wind pressure zones includes:

[0036] According to the wind pressure attenuation ratio, a region where the wind pressure attenuation ratio is less than the first wind pressure attenuation ratio is determined as a first wind pressure region, and / or,

[0037] Determine an area where the wind pressure attenuation ratio is greater than or equal to the first wind pressure attenuation ratio and less than the second wind pressure attenuation ratio as a second wind pressure area, and / or,

[0038] Determine an area where the wind pressure attenuation ratio is greater than or equal to a third wind pressure attenuation ratio as a third wind pressure area, wherein the first attenuation ratio is less than the second attenuation ratio;

[0039] For the first wind pressure zone, the second wind pressure zone and the third wind pressure zone, photovoltaic brackets with strengths corresponding to different wind pressure zones are arranged respectively.

[0040] Optionally, for the first wind pressure zone, the second wind pressure zone and the third wind pressure zone, photovoltaic brackets having strengths corresponding to the different wind pressure zones are arranged respectively, including:

[0041] In the first wind pressure area, a photovoltaic bracket with a first strength is arranged, wherein the photovoltaic bracket with the first strength indicates that the strength of the photovoltaic bracket is better than the design specification and the test standard;

[0042] In the second wind pressure zone, a photovoltaic bracket of a second strength is arranged, wherein the photovoltaic bracket of the second strength indicates that the strength of the photovoltaic bracket complies with the design plan and the test standard;

[0043] In the third wind pressure zone, a photovoltaic bracket of a third strength is arranged, and the photovoltaic bracket of the third strength indicates that the strength of the photovoltaic bracket is lower than the design specification and the test standard.

[0044] Optionally, the method further comprises:

[0045] Real-time monitoring of the typhoon wind speed at the location of the current project;

[0046] When the typhoon wind speed is greater than the preset wind speed, for the area where the photovoltaic components to be tested are located where the probability of hidden cracks exceeding the preset probability is located, anti-hidden crack protection measures such as active wind-proofing and flattening of the brackets are adopted.

[0047] Optionally, the method further comprises:

[0048] Obtaining a wind pressure area where the photovoltaic component is located in an actual photovoltaic array, wherein the wind pressure area includes: a positive wind pressure area, a negative wind pressure area, or a lateral wind pressure area;

[0049] The probability of at least one of the hidden crack types occurring in the photovoltaic components in any of the wind pressure areas is determined according to the wind load in any of the wind pressure areas and the corresponding relationship between the mechanical load and the hidden crack type.

[0050] This application has the following advantages:

[0051] The embodiment of the present application provides a method for resisting hidden cracks of photovoltaic modules, the method comprising: performing a mechanical load test on the photovoltaic modules to be tested, classifying the hidden cracks occurring on the photovoltaic modules to be tested, and determining the correspondence between the mechanical load applied to the photovoltaic modules to be tested and the classified hidden crack types; obtaining the basic load at the current project location, and determining the probability of occurrence of at least one type of hidden cracks according to the basic load; partitioning a standard photovoltaic array composed of a plurality of the photovoltaic modules to be tested according to the attenuation ratio of wind pressure to obtain a plurality of wind pressure partitions; and protecting the photovoltaic modules to be tested against hidden cracks according to the probability of occurrence of at least one type of hidden cracks and / or the plurality of wind pressure partitions. The present application classifies the hidden cracks on the photovoltaic modules to be tested, and determines the probability of occurrence of different types of hidden cracks, and partitions the photovoltaic array into wind pressure partitions to determine a plurality of wind pressure partitions, and finally adopts different anti-hidden crack protection measures according to the probability of occurrence of different types of hidden cracks and different wind pressure partitions, so that the photovoltaic modules can be more comprehensively protected against hidden cracks, and the escape of risk factors leading to hidden cracks can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 This is a schematic diagram of the steps of a method for resisting hidden cracks in a photovoltaic module provided in an embodiment of the present application;

[0054] Figure 2 It is a schematic diagram of wind pressure on a photovoltaic array under different wind direction conditions in a digital simulated wind tunnel provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] The exemplary embodiments of the present application will be described in more detail below in conjunction with the accompanying drawings in the embodiments of the present application. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to enable the scope of the present application to be fully communicated to those skilled in the art.

[0056] At present, in order to adapt to multi-scenario photovoltaic power generation projects, large-span flexible brackets are gradually replacing small-span dense column-type purlin-type photovoltaic brackets. However, large-span flexible brackets have a significant change in the supporting strength and rigidity of photovoltaic modules, resulting in an increased risk of hidden cracks in the modules, which is mainly reflected in:

[0057] (1) Traditional brackets use 40 mm wide steel purlins to support the four long sides of the photovoltaic module, which is a surface contact; flexible brackets use 15.2 mm diameter steel strands to support the four long sides of the module, which is a line contact. Under the same gravity load and wind load conditions, the contact stress of line contact is more than 8 times that of surface contact. The rapid increase in contact stress will lead to large plastic deformation of the module support parts, causing the photovoltaic module to bend significantly, thereby increasing the risk of hidden cracks.

[0058] (2) The two steel purlins of the traditional bracket supporting the photovoltaic module are fixed with a crossbeam, which can be considered as a rigid constraint. When the photovoltaic module is subjected to gravity load and wind load, there will be no relative movement. There is no constraint between the two steel strands of the flexible bracket supporting the photovoltaic module. When the photovoltaic module is subjected to gravity load and wind load, there will be relative movement. The flexible bracket tends to get closer to the supporting point of the photovoltaic module, which means that the rigidity of the module support is insufficient, increasing the risk of hidden cracks.

[0059] (3) The east-west distance between the columns of the traditional bracket is about 6 meters, and the columns are supported by rigid beams to support the photovoltaic modules, which can maintain rigidity under wind load and basically does not produce low-frequency vibration; the east-west distance between the columns of the flexible bracket is greater than 15 meters, and the columns are supported by flexible steel cables to support the photovoltaic modules, which are prone to low-frequency vibration under wind load. Low-frequency vibration will greatly increase the risk of hidden cracks in the modules.

[0060] (4) Traditional supports cannot automatically flatten under extreme wind speed conditions and can only avoid deformation and component cracking by increasing the rigidity of the support, which keeps the construction cost high. Due to the huge span and flexible support characteristics of flexible supports, even if the diameter of the steel strand is increased, there is no substantial improvement in improving the support rigidity. The risk of component cracking is greatly increased due to the introduction of flexible supports.

[0061] Therefore, in a first aspect of the present application, a method for preventing hidden cracks in a photovoltaic module is provided. Figure 1 As shown:

[0062] Step S101, performing a mechanical load test on the photovoltaic module to be tested, classifying the hidden cracks occurring on the photovoltaic module to be tested, and determining the corresponding relationship between the mechanical load applied to the photovoltaic module to be tested and the classified hidden crack types;

[0063] Step S102, obtaining the basic load of the current project location, and determining the probability of occurrence of at least one type of hidden crack according to the basic load;

[0064] Step S103, partitioning a standard photovoltaic array composed of a plurality of photovoltaic modules to be tested according to wind pressure attenuation ratios to obtain a plurality of wind pressure partitions;

[0065] Step S104: performing anti-hidden crack protection on the photovoltaic assembly to be tested according to the probability of occurrence of the at least one hidden crack type and / or the plurality of wind pressure zones.

[0066] Specifically, in the embodiment of the present application, a mechanical load test is performed on the photovoltaic module to be tested, so as to continuously apply mechanical load to the photovoltaic module to be tested, so as to gradually cause hidden cracks in the photovoltaic module to be tested, thereby simulating the hidden cracks generated in the photovoltaic module under the action of wind load in actual applications.

[0067] Furthermore, by observing the hidden cracks generated on the photovoltaic module to be tested, these hidden cracks are classified according to the areas where different hidden cracks are located. It should be noted that while the mechanical load is continuously applied to the photovoltaic module to be tested, it is necessary to record the mechanical load applied to the photovoltaic module to be tested when the hidden cracks are generated, so as to determine the mechanical load corresponding to each type of hidden crack when different hidden cracks are generated on the photovoltaic module to be tested. In practical applications, by performing mechanical load tests on the photovoltaic module to be tested, the types of hidden cracks generated on the photovoltaic module to be tested and the mechanical loads applied to the photovoltaic module to be tested when the types of hidden cracks are generated are sorted out to obtain a multi-factor classification matrix database of module hidden crack boundary conditions, which contains the corresponding relationships between multiple hidden crack types and their corresponding mechanical loads.

[0068] Furthermore, by obtaining the basic load at the current project location and according to the basic load and the corresponding relationship between the hidden crack type and the mechanical load obtained in the previous step, the probability of occurrence of each hidden crack type is determined.

[0069] Furthermore, a plurality of photovoltaic modules to be tested are combined into a standard photovoltaic array, and the standard photovoltaic array is divided into different wind pressure zones according to the wind pressure attenuation in different areas of the standard photovoltaic array.

[0070] Finally, the photovoltaic modules are protected against hidden cracks according to the probability of occurrence of the hidden crack types, and / or the photovoltaic modules to be tested are protected against hidden cracks according to different wind pressure zones of the standard photovoltaic array.

[0071] In a preferred embodiment, the photovoltaic module to be tested is subjected to a mechanical load test to classify the hidden cracks occurring on the photovoltaic module to be tested, including: performing an initial EL test on the photovoltaic module to be tested to determine that no hidden cracks occur in the photovoltaic module to be tested; applying a mechanical load to the photovoltaic module to be tested that has no hidden cracks, and observing the hidden cracks of the photovoltaic module to be tested through a post-test EL test; and classifying the hidden cracks on the photovoltaic module to be tested according to the areas where the hidden cracks are located.

[0072] Specifically, before performing a mechanical load test on the photovoltaic module to be tested, an EL test needs to be performed on the photovoltaic module to be tested to ensure that the photovoltaic module to be tested is an intact photovoltaic module without hidden cracks, thereby ensuring the accuracy of the test data.

[0073] Furthermore, after determining that the photovoltaic module to be tested is an intact photovoltaic module without hidden cracks, a mechanical load is applied to the photovoltaic module, and the hidden cracks of the photovoltaic module to be tested are observed through an EL test after the test. It should be noted that the applied mechanical load is a uniform mechanical load.

[0074] Finally, the hidden cracks are classified according to the area where the hidden cracks are located on the photovoltaic module to be tested. In practical applications, the hidden cracks can be divided into four categories according to the area where the hidden cracks are located: local deformation hidden cracks at the four-point support part, overall concave deformation hidden cracks at the middle part of the module, hidden cracks in the area connecting the two support points parallel to the short side, and sporadic hidden cracks.

[0075] In this embodiment, hidden cracks are generated on the photovoltaic module to be tested through mechanical load testing, and the hidden cracks are classified according to the areas where the hidden cracks are located on the photovoltaic module to be tested, so that corresponding anti-hidden crack protection measures can be taken according to different types of hidden cracks.

[0076] In a preferred embodiment of the present application, determining the correspondence between the mechanical load applied to the photovoltaic component to be tested and the classified hidden crack type includes: when performing the mechanical load test on the photovoltaic component to be tested, monitoring the attenuation of the current of the photovoltaic component to be tested; recording the hidden crack type occurring on the photovoltaic component to be tested and the mechanical load corresponding to the hidden crack type every time the attenuation increases by a preset step; when the attenuation reaches the preset attenuation, determining the correspondence between each hidden crack type and the mechanical load, and the mechanical load test includes a front mechanical static load test, a back mechanical static load test or a mechanical dynamic load.

[0077] When a mechanical load is applied to the photovoltaic module to be tested and the test is carried out, the current attenuation of the photovoltaic module is monitored at the same time. Current attenuation refers to the phenomenon that the current of the photovoltaic module gradually decreases under the action of mechanical load. Therefore, as the mechanical load applied to the photovoltaic module to be tested gradually increases, the hidden cracks on the photovoltaic module to be tested also gradually increase, and therefore, the current attenuation also continues to increase.

[0078] Furthermore, every time the current attenuation rises to a preset step length, the type of hidden cracks occurring on the photovoltaic module to be tested and the mechanical load corresponding to the hidden crack type are recorded. In practical applications, the preset step length may be based on the initial current value, with each 1% decrease in the current value being a step length. It should be noted that when the attenuation of the current value reaches 5%, the test is stopped. By recording the type of hidden cracks of the photovoltaic module to be tested at each step length and the mechanical load at the step length, the corresponding relationship between the hidden crack type and the mechanical load can be determined, that is, the photovoltaic module to be tested may have different hidden crack types under different mechanical loads.

[0079] In practical applications, the mechanical load test may include a front mechanical static load test, a back mechanical static load test, or a mechanical dynamic load test. When the mechanical load test is a front mechanical static load test, the corresponding relationship between the hidden crack type and the front mechanical static load can be determined; when the mechanical load test is a back mechanical static load test, the corresponding relationship between the hidden crack type and the back mechanical static load can be determined; when the mechanical load test is a mechanical dynamic load test, the corresponding relationship between the hidden crack type and the mechanical dynamic load can be determined.

[0080] In this embodiment, by establishing a correlation between mechanical load and hidden crack type, the performance and reliability of photovoltaic modules under different stresses can be better determined, and appropriate maintenance and improvement measures can be taken, which helps to improve the quality and power generation efficiency of photovoltaic modules.

[0081] In a preferred embodiment of the present application, the basic load data includes: wind and snow load, gravity load and seismic load; the basic load of the current project location is obtained, and the probability of occurrence of at least one type of hidden crack is determined according to the basic load, including: obtaining comprehensive geographical information of the project location, as well as the bracket height and component inclination of the photovoltaic component to be tested; based on the comprehensive geographical information, the weight coefficients corresponding to the wind and snow load, the gravity load and the seismic load are determined; based on the weight coefficient, the wind and snow load, the gravity load and the seismic load are weighted and summed to obtain the basic comprehensive load; according to the bracket height and the component inclination, the shape coefficient, gust coefficient and height coefficient of the photovoltaic component to be tested are determined; according to the shape coefficient, the gust coefficient and the height coefficient, the comprehensive load corresponding to the basic comprehensive load is determined; according to the correspondence between the comprehensive load and the mechanical load applied to the photovoltaic component to be tested and at least one of the hidden crack types, the probability of occurrence of at least one of the hidden crack types is determined.

[0082] In this embodiment, basic load data of the current project location is obtained, wherein the basic load data includes: wind and snow load, gravity load and earthquake load. It should be noted that the basic load data of the current project location can be obtained from relevant departments or data providers, and this application does not make specific limitations here.

[0083] Furthermore, after obtaining the basic load data of the current project location, the probability of occurrence of at least one type of hidden cracks as described above is determined through the basic load data of the current project location, specifically including: obtaining comprehensive geographic information of the project location. In practical applications, the comprehensive geographic information may include geographic coordinates, altitude, meteorological data, etc. This information can be obtained from the Meteorological Bureau, Geographic Information System (GIS) database, local relevant departments and other institutions; based on the meteorological data and geographic information of the project location, the wind and snow load can be calculated. In practical applications, factors affecting the wind and snow load may include wind speed, wind direction, snow load, etc. Therefore, when calculating the wind and snow load, it is necessary to use relevant wind load and snow load standards or specifications for calculation; secondly, gravity load data can also be obtained through local relevant departments or research institutions; for seismic loads, depending on the level of seismic activity at the project location, the seismic parameters and seismic load standards of the seismic area can be used to determine the seismic load.

[0084] Furthermore, according to the comprehensive geographical information of the project location and taking into account the relative importance of different loads, the weight coefficients corresponding to the wind and snow load, gravity load and earthquake load are determined, and the basic comprehensive load is obtained by weighted summation based on the wind and snow load, gravity load, earthquake load and their corresponding weight coefficients;

[0085] Further, the shape factor, gust factor and height factor of the photovoltaic module to be tested are determined according to the measured bracket height of the photovoltaic module to be tested and the size of the inclination angle of the module, so as to further determine the comprehensive load of the photovoltaic module to be tested;

[0086] Furthermore, the type of hidden cracks occurring on the photovoltaic module to be tested and the size of the mechanical load corresponding to the hidden crack type applied to the photovoltaic module to be tested are determined, and the probability of occurrence of the hidden crack type is obtained by dividing the comprehensive load by the mechanical load corresponding to the hidden crack type occurring on the photovoltaic module to be tested.

[0087] In a preferred embodiment of the present application, the types of hidden cracks include: local deformation hidden cracks at four-point support parts, overall concave deformation hidden cracks at the middle part of the component, hidden cracks in the area connecting the two support points parallel to the short side, and at least one of sporadic hidden cracks; according to the probability of occurrence of at least one type of hidden cracks, the photovoltaic component to be tested is protected against hidden cracks, including: for the local deformation hidden cracks at the four-point support parts, taking anti-hidden crack protection measures of increasing the area of ​​the lower support surface of the photovoltaic component to be tested; for the overall concave deformation hidden cracks at the middle part of the component, taking anti-hidden crack protection measures of adding auxiliary support to the middle area of ​​the photovoltaic component to be tested; for the hidden cracks in the area connecting the two support points parallel to the short side, taking anti-hidden crack protection measures of changing the steel strand and the lower support point of the photovoltaic component to be tested to multi-point support; for the sporadic hidden cracks, taking anti-hidden crack protection measures of adding damping or elastic buffering in the middle of the span of the steel strand, or adding an elastic pad at the contact part between the photovoltaic component to be tested and the steel strand.

[0088] Specifically, in this embodiment, the types of hidden cracks include local deformation and hidden cracks at the four-point support part, overall concave deformation and hidden cracks at the middle part of the component, hidden cracks in the area connecting the two support points parallel to the short side, and sporadic hidden cracks. For the above four types of hidden cracks, this embodiment specifically adopts the following anti-hidden crack protection:

[0089] For local deformation and cracking of four-point support parts: In order to prevent local deformation and cracking, measures are taken to increase the area of ​​the support surface under the PV module to be tested. This can be achieved by increasing the number of support points or expanding the area of ​​the support points to disperse the load and reduce local stress.

[0090] For the overall concave deformation and cracking in the middle of the module: In order to prevent the overall concave deformation and cracking, add auxiliary support in the middle area of ​​the PV module to be tested. This can be achieved by adding additional support structures or support materials to provide additional support and stability.

[0091] For the hidden cracks in the area connecting the two supporting points parallel to the short side: To prevent this type of hidden cracks, the lower supporting point of the steel strand and the photovoltaic module to be tested is changed to multi-point support. This can reduce the stress concentration in the connecting area and increase the stability of the module.

[0092] For sporadic cracks: In order to prevent sporadic cracks, damping and elastic buffering are added in the middle of the steel strand span, or elastic pads are added at the contact point between the photovoltaic module and the steel strand. These measures can reduce vibration and stress transfer, thereby reducing the risk of sporadic cracks.

[0093] This embodiment adopts different anti-hidden crack protection measures according to different hidden crack types, which can more comprehensively protect photovoltaic modules from hidden cracks.

[0094] In a preferred embodiment of the present application, the standard photovoltaic array composed of the multiple photovoltaic components to be tested is partitioned according to the wind pressure attenuation ratio to obtain multiple wind pressure zones, including: performing a digital simulation wind tunnel test on the standard photovoltaic array composed of the multiple photovoltaic components to be tested; based on the digital simulation wind tunnel test, determining the wind pressure attenuation ratio of different areas of the standard photovoltaic array; and performing wind pressure partitioning on the standard photovoltaic array according to the wind pressure attenuation ratio.

[0095] Among them, for the multiple wind pressure zones, the photovoltaic components to be tested are protected against hidden cracks, including: according to the wind pressure attenuation ratio, the area where the wind pressure attenuation ratio is less than the first wind pressure attenuation ratio is determined as the first wind pressure zone, and / or, the area where the wind pressure attenuation ratio is greater than or equal to the first wind pressure attenuation ratio and less than the second wind pressure attenuation ratio is determined as the second wind pressure zone, and / or, the area where the wind pressure attenuation ratio is greater than or equal to the third wind pressure attenuation ratio is determined as the third wind pressure zone, wherein the first attenuation ratio is less than the second attenuation ratio; for the first wind pressure zone, the second wind pressure zone and the third wind pressure zone, photovoltaic brackets with strengths corresponding to different wind pressure zones are respectively arranged.

[0096] In addition, photovoltaic brackets with corresponding strengths to the different wind pressure zones are arranged in the first wind pressure zone, the second wind pressure zone and the third wind pressure zone, respectively, including: in the first wind pressure zone, photovoltaic brackets with a first strength are arranged, and the photovoltaic brackets with the first strength indicate that the strength of the photovoltaic bracket is better than the design specifications and the test standards; in the second wind pressure zone, photovoltaic brackets with a second strength are arranged, and the photovoltaic brackets with the second strength indicate that the strength of the photovoltaic bracket complies with the design plan and the test standards; in the third wind pressure zone, photovoltaic brackets with a third strength are arranged, and the photovoltaic brackets with the third strength indicate that the strength of the photovoltaic bracket is lower than the design specifications and the test standards.

[0097] Specifically, in this embodiment, a digital simulation wind tunnel test is performed on a standard photovoltaic array area. Figure 2 As shown in the figure, a digital simulation wind tunnel is used to simulate the wind pressure on the photovoltaic array under different wind direction conditions; further, the static wind pressure and dynamic wind pressure at the four outermost edges of the array area are observed and recorded. These data help determine the initial conditions of the wind pressure, and then, starting from the surrounding areas and gradually moving toward the center of the array, the attenuation ratio of the static wind pressure and dynamic wind pressure is summarized; further, the wind pressure is divided according to the attenuation ratio, and different anti-hidden crack protection measures are taken according to different wind pressure divisions.

[0098] Specifically, in this embodiment, the area where the wind pressure attenuation ratio is less than the first wind pressure attenuation ratio is determined as the first wind pressure area, and / or the area where the wind pressure attenuation ratio is greater than or equal to the first wind pressure attenuation ratio and less than the second wind pressure attenuation ratio is determined as the second wind pressure area, and / or the area where the wind pressure attenuation ratio is greater than or equal to the third wind pressure attenuation ratio is determined as the third wind pressure area, wherein the first attenuation ratio is less than the second attenuation ratio; for the first wind pressure area, the second wind pressure area and the third wind pressure area, photovoltaic brackets with strengths corresponding to the different wind pressure areas are arranged respectively. Among them, the first wind pressure area is the area with the largest wind pressure. In this embodiment, high-strength photovoltaic brackets are arranged in the first wind pressure area, and the strength of these photovoltaic brackets is much higher than the design specifications and test standards to ensure that they can withstand high wind pressure. For the second wind pressure area, the wind pressure intensity is slightly lower than that of the first wind pressure area. Therefore, in the second wind pressure area, photovoltaic brackets that meet the design specifications and test standards are arranged to meet normal wind pressure requirements. For the third wind pressure area, the wind pressure intensity is relatively low. Therefore, photovoltaic brackets with lower strength are arranged in the third wind pressure area, and the strength of these brackets is lower than the design specifications and test standards.

[0099] In practical applications, when the wind pressure is positive, the area on the southernmost side of the photovoltaic array that bears the maximum positive wind pressure is defined as the first wind pressure zone; based on the first wind pressure zone, the area where the positive wind pressure decays by 20% is defined as the second wind pressure zone, and the area where the positive wind pressure decays by 50% is defined as the third wind pressure zone; when the wind pressure is negative, the area on the northernmost side that bears the maximum negative wind pressure is defined as the first wind pressure zone; based on the first wind pressure zone, the area where the negative wind pressure decays by 20% is defined as the second wind pressure zone, and the area where the negative wind pressure decays by 50% is defined as the third wind pressure zone; when the wind pressure is lateral, the area on the east or west side that bears the maximum wind pressure is defined as the first wind pressure zone; based on the first wind pressure zone, the area where the wind pressure decays by 10% is defined as the second wind pressure zone, and the area where the negative wind pressure decays by 20% is defined as the third wind pressure zone.

[0100] In this embodiment, different strength brackets are selected for photovoltaic modules according to the wind pressure conditions in different areas to ensure that they can work normally under different wind pressure conditions and reduce the risk of hidden cracks. At the same time, photovoltaic brackets of corresponding strength are arranged according to different wind pressures, which helps to reduce the cost of project construction.

[0101] In a preferred embodiment of the present application, the method further includes: real-time monitoring of the typhoon wind speed at the location of the current project; when the typhoon wind speed is greater than a preset wind speed, for areas where the photovoltaic components to be tested are located where the probability of hidden cracks exceeding a preset probability is located, taking anti-hidden crack protection measures such as actively flattening the brackets to prevent wind.

[0102] Specifically, when a typhoon comes, the typhoon wind speed at the project site is monitored in real time to ensure that the typhoon wind conditions are understood in real time. When the monitored typhoon wind speed reaches or exceeds the preset wind speed threshold, the standard photovoltaic array system will automatically identify the areas where the probability of hidden cracks occurring in the photovoltaic modules to be tested exceeds the preset probability. These areas may be affected by higher wind pressure, thereby increasing the risk of hidden cracks. The system will take anti-hidden crack protection measures such as active windproof and flattening of the bracket to reduce the pressure of the typhoon on the photovoltaic modules, thereby reducing the risk of hidden cracks and protecting the photovoltaic modules from the impact of the typhoon.

[0103] This embodiment increases the robustness of photovoltaic modules by taking anti-hidden crack protection measures such as actively flattening the brackets in areas with a high probability of hidden cracks, so as to cope with extreme weather conditions such as typhoons, thereby ensuring the safe and stable operation of photovoltaic modules. Through real-time monitoring and active wind protection measures, the standard photovoltaic array system can better cope with sudden high wind speeds and reduce the risk of hidden cracks.

[0104] In a preferred embodiment of the present application, the wind pressure area where the photovoltaic component is located in the actual photovoltaic array is obtained, and the wind pressure area includes: a positive wind pressure area, a negative wind pressure area or a lateral wind pressure area; based on the wind load in any of the wind pressure areas and the correspondence between the mechanical load and the hidden crack type, the probability of at least one of the hidden crack types occurring in the photovoltaic component in any of the wind pressure areas is determined.

[0105] Specifically, as shown in Tables 1-3 below, they are respectively a table of correspondence between wind loads in different wind pressure zones and front mechanical static loads and hidden crack types, a table of correspondence between wind loads in different wind pressure zones and back mechanical static loads and hidden crack types, and a table of correspondence between wind loads in different wind pressure zones and mechanical dynamic loads and hidden crack types provided in the present application.

[0106]

[0107] Table 1

[0108]

[0109] Table 2

[0110]

[0111] Table 3

[0112] It can be seen from Table 1-3 that for the four types of hidden cracks, namely local deformation and hidden cracks at the four-point support part, overall concave deformation and hidden cracks in the middle part of the component, hidden cracks in the area connecting the two support points parallel to the short side, and sporadic hidden cracks, the probability of hidden cracks occurring is different under wind pressure in different directions. By analyzing the relationship between wind load and hidden crack type in the positive wind pressure area, negative wind pressure area, and lateral wind pressure area, the photovoltaic brackets at the project site can be better protected against hidden cracks.

[0113] The embodiment of the present application provides a method for resisting hidden cracks of photovoltaic modules, the method comprising: performing a mechanical load test on the photovoltaic modules to be tested, classifying the hidden cracks occurring on the photovoltaic modules to be tested, and determining the correspondence between the mechanical load applied to the photovoltaic modules to be tested and the classified hidden crack types; obtaining the basic load at the current project location, and determining the probability of occurrence of at least one type of hidden cracks according to the basic load; partitioning a standard photovoltaic array composed of a plurality of the photovoltaic modules to be tested according to the attenuation ratio of wind pressure to obtain a plurality of wind pressure partitions; and protecting the photovoltaic modules to be tested against hidden cracks according to the probability of occurrence of at least one type of hidden cracks and / or the plurality of wind pressure partitions. The present application classifies the hidden cracks on the photovoltaic modules to be tested, and determines the probability of occurrence of different types of hidden cracks, and partitions the photovoltaic array into wind pressure partitions to determine a plurality of wind pressure partitions, and finally adopts different anti-hidden crack protection measures according to the probability of occurrence of different types of hidden cracks and different wind pressure partitions, so that the photovoltaic modules can be more comprehensively protected against hidden cracks, and the escape of risk factors leading to hidden cracks can be avoided.

[0114] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0115] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0116] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0117] The above is a detailed introduction to a photovoltaic module anti-hidden crack method provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for preventing hidden cracks in photovoltaic modules, characterized in that: The method comprises: Performing a mechanical load test on the photovoltaic module to be tested, classifying the hidden cracks occurring on the photovoltaic module to be tested, and determining the corresponding relationship between the mechanical load applied to the photovoltaic module to be tested and the classified hidden crack types; Obtaining a basic load at a current project location, and determining a probability of occurrence of at least one type of hidden crack according to the basic load; Partitioning a standard photovoltaic array composed of a plurality of photovoltaic modules to be tested according to a wind pressure attenuation ratio to obtain a plurality of wind pressure partitions; According to the probability of occurrence of the at least one type of hidden cracks and / or the multiple wind pressure zones, the photovoltaic assembly to be tested is protected against hidden cracks.

2. The photovoltaic module anti-crack method according to claim 1, characterized in that: The mechanical load test is performed on the photovoltaic module to be tested, and the hidden cracks occurring on the photovoltaic module to be tested are classified, including: Performing an initial EL test on the photovoltaic module to be tested to determine that no hidden cracks occur in the photovoltaic module to be tested; Applying a mechanical load to the photovoltaic module to be tested without any hidden cracks, and observing the hidden cracks of the photovoltaic module to be tested through a post-test EL test; The hidden cracks on the photovoltaic assembly to be tested are classified according to the areas where the hidden cracks are located.

3. The photovoltaic module anti-crack method according to claim 1, characterized in that: The determining of the correspondence between the mechanical load applied to the photovoltaic assembly to be tested and the classified hidden crack type comprises: When performing the mechanical load test on the photovoltaic assembly to be tested, monitoring the attenuation of the current of the photovoltaic assembly to be tested; Each time the attenuation value increases by a preset step length, recording the type of hidden cracks occurring on the photovoltaic assembly to be tested and the mechanical load corresponding to the type of hidden cracks; When the attenuation reaches the preset attenuation, the corresponding relationship between each of the hidden crack types and the mechanical load is determined, and the mechanical load test includes a front mechanical static load test, a back mechanical static load test or a mechanical dynamic load test.

4. The photovoltaic module anti-crack method according to claim 1, characterized in that: The basic load data includes: wind and snow load, gravity load and earthquake load; the basic load of the current project location is obtained, and the probability of occurrence of at least one type of hidden crack is determined according to the basic load, including: Obtaining comprehensive geographic information of the project location, as well as the bracket height and component inclination angle of the photovoltaic component to be tested; Based on the comprehensive geographic information, determining weight coefficients corresponding to the wind and snow load, the gravity load, and the earthquake load; Based on the weight coefficient, weighted sum of the wind and snow load, the gravity load and the earthquake load is performed to obtain a basic comprehensive load; Determining the shape factor, gust factor and height factor of the photovoltaic module to be tested according to the bracket height and the module inclination angle; Determining a comprehensive load corresponding to the basic comprehensive load according to the shape coefficient, the gust coefficient and the height coefficient; The probability of occurrence of at least one of the hidden crack types is determined according to the corresponding relationship between the comprehensive load and the mechanical load applied to the photovoltaic assembly to be tested and at least one of the hidden crack types.

5. The method for preventing hidden cracks in photovoltaic modules according to any one of claims 1 to 4, characterized in that: The hidden crack types include: local deformation and hidden cracks at four-point support parts, overall concave deformation and hidden cracks at the middle part of the component, hidden cracks in the area connecting the two support points parallel to the short side, and sporadic hidden cracks; the anti-hidden crack protection of the photovoltaic component to be tested based on the probability of occurrence of at least one hidden crack type includes: In view of the local deformation and cracking of the four-point support parts, anti-crack protection measures are taken to increase the area of ​​the lower support surface of the photovoltaic module to be tested; In view of the overall concave deformation and hidden cracks in the middle part of the module, an anti-hidden crack protection measure is taken to add auxiliary support to the middle area of ​​the photovoltaic module to be tested; In view of the hidden cracks in the area connecting the two supporting points parallel to the short side, a protective measure against hidden cracks is adopted, in which the lower supporting point of the steel strand and the photovoltaic module to be tested is changed to a multi-point support; To address the sporadic hidden cracks, anti-hidden crack protection measures are taken such as adding damping and elastic buffering in the middle of the steel strand span, or adding elastic pads at the contact point between the photovoltaic module to be tested and the steel strand.

6. The photovoltaic module anti-crack method according to claim 1, characterized in that: The standard photovoltaic array composed of the plurality of photovoltaic modules to be tested is partitioned according to the attenuation ratio of the wind pressure to obtain a plurality of wind pressure partitions, including: Performing a digital simulation wind tunnel test on a standard photovoltaic array composed of a plurality of photovoltaic modules to be tested; Based on the digital simulation wind tunnel test, determining the wind pressure attenuation ratios of different areas of the standard photovoltaic array; The standard photovoltaic array is divided into wind pressure zones according to the wind pressure attenuation ratio.

7. The photovoltaic module anti-crack method according to claim 6, characterized in that: The step of performing anti-hidden crack protection on the photovoltaic assembly to be tested for the plurality of wind pressure zones includes: According to the wind pressure attenuation ratio, a region where the wind pressure attenuation ratio is less than the first wind pressure attenuation ratio is determined as a first wind pressure region, and / or, Determine an area where the wind pressure attenuation ratio is greater than or equal to the first wind pressure attenuation ratio and less than the second wind pressure attenuation ratio as a second wind pressure area, and / or, Determine an area where the wind pressure attenuation ratio is greater than or equal to a third wind pressure attenuation ratio as a third wind pressure area, wherein the first attenuation ratio is less than the second attenuation ratio; For the first wind pressure zone, the second wind pressure zone and the third wind pressure zone, photovoltaic brackets with strengths corresponding to different wind pressure zones are arranged respectively.

8. The photovoltaic module anti-hidden cracking method according to claim 7, characterized in that: The photovoltaic brackets having strengths corresponding to the different wind pressure zones are arranged respectively for the first wind pressure zone, the second wind pressure zone and the third wind pressure zone, including: In the first wind pressure area, a photovoltaic bracket with a first strength is arranged, wherein the photovoltaic bracket with the first strength indicates that the strength of the photovoltaic bracket is better than the design specification and the test standard; In the second wind pressure zone, a photovoltaic bracket of a second strength is arranged, wherein the photovoltaic bracket of the second strength indicates that the strength of the photovoltaic bracket complies with the design plan and the test standard; In the third wind pressure zone, a photovoltaic bracket of a third strength is arranged, and the photovoltaic bracket of the third strength indicates that the strength of the photovoltaic bracket is lower than the design specification and the test standard.

9. The method for preventing hidden cracks in photovoltaic modules according to any one of claims 1 to 4 or any one of claims 6 to 7, characterized in that: The method further comprises: Real-time monitoring of the typhoon wind speed at the location of the current project; When the typhoon wind speed is greater than the preset wind speed, for the area where the photovoltaic components to be tested are located where the probability of hidden cracks exceeding the preset probability is located, anti-hidden crack protection measures such as active wind-proofing and flattening of the brackets are adopted.

10. The photovoltaic module anti-crack method according to claim 1, characterized in that: The method further comprises: Obtaining a wind pressure area where the photovoltaic component is located in an actual photovoltaic array, wherein the wind pressure area includes: a positive wind pressure area, a negative wind pressure area, or a lateral wind pressure area; The probability of at least one of the hidden crack types occurring in the photovoltaic components in any of the wind pressure areas is determined according to the wind load in any of the wind pressure areas and the corresponding relationship between the mechanical load and the hidden crack type.

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