A method for testing photovoltaic module encapsulation film

Abstract

The present invention discloses a method for testing a photovoltaic module encapsulation film, which relates to the technical field of photovoltaic material testing, including sample preparation, initial testing, environmental treatment, post-environmental testing and result determination. When making samples, the front glass is divided into two left and right areas, one of which is firstly coated with an isolation film, an encapsulation film, and an isolation film, and then the two areas are integrally coated with an encapsulation film, a battery layer, and an encapsulation film to make 6 samples. In the initial test, the films of 3 samples are tested for resistivity and breakdown voltage, and the test is terminated if the conditions are not met. After environmental treatment, the remaining 3 samples are tested for light and current overload, and then the film performance is tested. Finally, whether the film is qualified is determined based on the test results. The present invention can effectively verify the changes in the electrical properties of the encapsulation film by prefabricating the encapsulation film sample on the front of the test sample photovoltaic module, and performing environmental tests and encapsulation film tests on the test samples, which is helpful to evaluate the adaptability of the film in different environments.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic material testing, and in particular to a method for testing a photovoltaic component encapsulation film. Background Art

[0002] Solar photovoltaic modules, commonly known as photovoltaic panels or solar panels, are devices that use solar energy to directly convert light energy into electrical energy. The core components of solar photovoltaic modules are semiconductor materials, which are protected by encapsulation films. Generally, solar photovoltaic modules are composed of tempered glass, transparent encapsulation films, cell layers, transparent encapsulation films, and backplanes stacked from bottom to top. The cell layers are composed of several parallel cell strings and busbars used to connect the welding strips of each cell string, and are encapsulated by vacuum heating, lamination, curing and encapsulation. The material, formula and process of the encapsulation film play a vital role in the performance and reliability of photovoltaic modules. At present, the electrical reliability tests of encapsulation films mainly include volume resistivity tests and breakdown voltage tests, which are based on simulated samples of lamination-like processes. They cannot verify the changes in the electrical performance of the encapsulation film during the outdoor operation of photovoltaic modules, and there is a risk of reliability failure.

[0003] In view of this, a photovoltaic module encapsulation film testing method is urgently needed to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a photovoltaic module packaging film testing method to effectively verify the electrical performance changes of the packaging film and solve the above-mentioned problems existing in the prior art.

[0005] To achieve the above object, the present invention provides the following solution: a photovoltaic module encapsulation film testing method, comprising the following steps:

[0006] S1. Sample preparation: the front glass is divided into two areas, left and right, along the length direction. In one of the areas, the first transparent isolation film, the third packaging film, and the second transparent isolation film are laid layer by layer; wherein the area of ​​the first transparent isolation film and the second transparent isolation film are both 1 / 2 of the size of the front glass, and overlap each other from top to bottom; the first packaging film, the battery layer, the second packaging film, and the backplane are laid on the front glass to obtain a test sample. Six test samples are prepared and numbered M1 to M6;

[0007] S2. Initial test of packaging film: take out the third packaging film from the test samples numbered M1, M2, and M3, and conduct volume resistivity and breakdown voltage tests. The test results are recorded as TJ1, TJ2, TJ3 and JC1, JC2, and JC3 respectively. When TJ1, TJ2, and TJ3 are all ≥1*10 14 And JC1, JC2, JC3 are all>28KV / cm 2If the test is successful, the test continues; otherwise, the test is terminated.

[0008] S3, sample environment treatment, perform illumination test on the test samples numbered M4, M5, and M6, and perform reverse current overload test after illumination test;

[0009] S4, performing a post-encapsulation film test on the test samples after the treatment in step S3, taking out the third encapsulation film from the test samples numbered M4, M5, and M6, and performing volume resistivity and breakdown voltage tests, and the test results are recorded as TJ4, TJ5, TJ6 and JC4, JC5, and JC6 respectively;

[0010] S6. Result determination: determine whether the encapsulation film is qualified based on the test results TJ4, TJ5, TJ6 and JC4, JC5, JC6.

[0011] In some optional implementations, in step S6, the result determination includes:

[0012] If the volume resistivity TJ4, TJ5, and TJ6 are all ≥ 1*10 14 , the packaging film is judged to be qualified;

[0013] If any of the volume resistivity TJ4, TJ5, TJ6 does not satisfy ≥1*10 14 , it is judged that there is a risk;

[0014] If two or more of the volume resistivity TJ4, TJ5, and TJ6 do not meet the requirement of ≥1*10 14 , the packaging film is judged to be unqualified.

[0015] In some optional implementations, in step S6, the result determination includes:

[0016] If the breakdown voltage JC4, JC5, and JC6 are all greater than 28KV / cm 2 , the packaging film is judged to be qualified;

[0017] If one of the breakdown voltages JC4, JC5, and JC6 does not meet the requirement of >28KV / cm 2 , it is judged that there is a risk;

[0018] If two or more of the breakdown voltages JC4, JC5, and JC6 do not meet the requirement of >28KV / cm 2 , the packaging film is judged to be unqualified.

[0019] In some optional implementations, the illumination test in step S3 includes: 2 The test samples were tested under the conditions of 60KWh / m 2 of irradiation.

[0020] In some optional implementations, the reverse current overload test in step S3 includes: passing a current value of 1.35 times the rated current of the junction box fuse through the test sample for 2 hours.

[0021] In some optional implementations, in step S2 and step S4, the third packaging film encapsulated in the test sample is taken out by breaking the front glass.

[0022] The present invention discloses the following technical effects:

[0023] The testing of encapsulation film is crucial to ensure the performance, reliability and safety of photovoltaic modules, and is a key link in quality control and product optimization in the photovoltaic industry. The present invention can effectively verify the changes in the electrical properties of the encapsulation film by prefabricating the encapsulation film sample on the front of the test sample photovoltaic module and performing environmental tests and encapsulation film tests on the test sample, which helps to evaluate the adaptability of the film in different environments, such as weather resistance and heat resistance, and ensure that the module can operate stably under various climatic conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 Schematic diagram of the layer structure of the test sample of the present invention;

[0026] Figure 2 It is a schematic diagram of the front structure of the test sample of the present invention;

[0027] Figure 3 Flow chart of the testing method of the present invention.

[0028] In the figure: 100, test sample; 101, front glass; 102, first packaging film; 103, battery layer; 104, second packaging film; 105, back plate; 106, first transparent isolation film; 107, third packaging film; 108, second transparent isolation film. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] As a key encapsulation material for photovoltaic modules, encapsulation film is directly related to the reliability and service life of the modules. The film covers the upper and lower surfaces of the cells to protect the cells from environmental influences, such as humidity and temperature changes, thereby extending the service life of the modules. The encapsulation film needs to operate for a long time in outdoor environments. In order to ensure that the modules can operate stably under various climatic conditions, it is necessary to simulate the impact of outdoor operating conditions on the encapsulation film, and then test and evaluate the adaptability of the film in different environments, such as weather resistance and heat resistance. In summary, the testing of encapsulation film is crucial to ensuring the performance, reliability and safety of photovoltaic modules, and is a key link in quality control and product optimization in the photovoltaic industry.

[0031] In view of the problem that the testing methods of the prior art cannot verify the changes in the electrical properties of the packaging film of photovoltaic modules during outdoor operation, and there is a risk of reliability failure, the present invention proposes a testing method for the packaging film of photovoltaic modules, which aims to prefabricate the packaging film sample on the front of the test sample module, and perform environmental tests and packaging film tests on the sample module, thereby effectively verifying the changes in the electrical properties of the packaging film.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Reference Figures 1 to 3 As shown, an embodiment of the present invention provides a photovoltaic module encapsulation film testing method, comprising the following steps:

[0034] S1. Sample production, including:

[0035] The front glass 101 is divided into two left and right regions along its length direction, and a first transparent isolation film 106, a third packaging film 107, and a second transparent isolation film 108 are applied layer by layer in one of the regions; wherein the first transparent isolation film 106 and the second transparent isolation film 108 are equal in size, and both have an area of ​​1 / 2 of the size of the front glass 101, and the two overlap from top to bottom, and the third packaging film 107 should not be larger in size than the first transparent isolation film 106 and the second transparent isolation film 108, and is located in the middle of the first transparent isolation film 106 and the second transparent isolation film 108;

[0036] After the above-mentioned laying is completed, the first packaging film 102, the battery layer 103, the second packaging film 104, and the back plate 105 are laid on the front glass 101 in sequence according to the laying process of conventional photovoltaic modules; it should be understood that the battery layer 103 referred to in this embodiment is a battery string after serial-parallel welding, and the battery string includes a plurality of battery cells, and the battery cells are connected in series in a manner of connecting the positive and negative electrodes using welding ribbons to obtain the battery string. The manufacturing process of the battery string and the laying process are both existing technologies and will not be described in detail here;

[0037] The laid product is made into a finished component according to a normal photovoltaic component production process to obtain a test sample 100; it should be understood that the normal photovoltaic component production process includes lamination, EL testing, framing, installation of junction boxes, curing, cleaning and finished product inspection, wherein the finished product inspection may include appearance inspection and performance inspection, and the performance inspection may include IV test, insulation withstand voltage test, grounding continuity test, etc.;

[0038] Six test samples 100 are manufactured using the same method and materials and are numbered M1, M2, M3, M4, M5, and M6 respectively.

[0039] S2. Initial test of packaging film, including:

[0040] Three test samples 100 numbered M1, M2, and M3 were taken for initial testing. First, the front glass 101 of the test sample 100 was broken by a glass impactor, and the third packaging film 107 was taken out.

[0041] The volume resistivity and breakdown voltage tests are performed on the removed third packaging film 107 , and the test results are recorded as TJ1 , TJ2 , TJ3 and JC1 , JC2 , JC3 , respectively.

[0042] Judging from the test results, the volume resistivity TJ1, TJ2, and TJ3 should all be ≥1*10 14 , breakdown voltage JC1, JC2, JC3 should all be > 28KV / cm 2 ;

[0043] If the test results do not meet the above requirements, the test should be terminated and the test sample 100 should be produced again according to step S1.

[0044] S3. Sample environment treatment, including:

[0045] Take 100 test samples numbered M4, M5 and M6, respectively, at 800-1000W / m 2 60KWh / m 2After the irradiation is completed, a reverse current overload test is performed, specifically, 100 test samples are subjected to a current of 1.35 times the rated current of the junction box fuse for 2 hours.

[0046] S4, packaging film test after environmental treatment, including:

[0047] The three test samples 100 numbered M4, M5, and M6 after the processing in step S3 are subjected to a post-test test. First, the front glass 101 of the test sample 100 is broken by a glass impactor, and the third packaging film 107 is taken out;

[0048] The volume resistivity and breakdown voltage tests are performed on the removed third packaging film 107 , and the test results are recorded as TJ4 , TJ5 , TJ6 and JC4 , JC5 , JC6 , respectively.

[0049] S5. Result determination

[0050] If the volume resistivity TJ4, TJ5, and TJ6 are all ≥ 1*10 14 , the packaging film is judged to be qualified;

[0051] If any of the volume resistivity TJ4, TJ5, TJ6 does not satisfy ≥1*10 14 , it is judged that there is a risk;

[0052] If two or more of the volume resistivity TJ4, TJ5, and TJ6 do not meet the requirement of ≥1*10 14 , the packaging film is judged to be unqualified and should be stopped from use;

[0053] If the breakdown voltage JC4, JC5, and JC6 are all greater than 28KV / cm 2 , the packaging film is judged to be qualified;

[0054] If one of the breakdown voltages JC4, JC5, and JC6 does not meet the requirement of >28KV / cm 2 , it is judged that there is a risk;

[0055] If two or more of the breakdown voltages JC4, JC5, and JC6 do not meet the requirement of >28KV / cm 2 , the packaging film is judged to be unqualified and should be discontinued.

[0056] The details not described in detail in the present invention are all conventional technical means well known to those skilled in the art.

[0057] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0058] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A photovoltaic module encapsulation film testing method, characterized in that: The following steps are involved: S1, sample preparation, dividing the front glass (101) into two left and right areas along the length direction, and laying a first transparent isolation film (106), a third packaging film (107), and a second transparent isolation film (108) layer by layer in one of the areas; wherein the area of ​​the first transparent isolation film (106) and the second transparent isolation film (108) are both 1 / 2 the size of the front glass (101), and overlap each other from top to bottom; laying a first packaging film (102), a battery layer (103), a second packaging film (104), and a back plate (105) on the front glass (101) to obtain a test sample (100), and making 6 test samples (100), numbered M1 to M6; S2, initial test of the packaging film, take out the third packaging film (107) from the test samples (100) numbered M1, M2, and M3, and perform volume resistivity and breakdown voltage tests, and record the test results as TJ1, TJ2, TJ3 and JC1, JC2, JC3 respectively; when TJ1, TJ2, and TJ3 are all ≥1*10 14 And JC1, JC2, JC3 are all>28KV / cm 2 If the test is successful, the test continues; otherwise, the test is terminated. S3, sample environment treatment, performing a light test on the test samples (100) numbered M4, M5, and M6, and performing a reverse current overload test after the light test; S4, performing a packaging film test on the test sample (100) after the treatment in step S3, taking out the third packaging film (107) in the test samples (100) numbered M4, M5, and M6, and performing volume resistivity and breakdown voltage tests, and recording the test results as TJ4, TJ5, TJ6 and JC4, JC5, and JC6 respectively; S6. Result determination: determine whether the encapsulation film is qualified based on the test results TJ4, TJ5, TJ6 and JC4, JC5, JC6.

2. The photovoltaic module encapsulation film testing method according to claim 1, characterized in that: In step S6, the result determination includes: If the volume resistivity TJ4, TJ5, and TJ6 are all ≥ 1*10 14 , the packaging film is judged to be qualified; If any of the volume resistivity TJ4, TJ5, TJ6 does not satisfy ≥1*10 14 , it is judged that there is a risk; If two or more of the volume resistivity TJ4, TJ5, and TJ6 do not meet the requirement of ≥1*10 14 , the packaging film is judged to be unqualified.

3. The photovoltaic module encapsulation film testing method according to claim 1 or 2, characterized in that: In step S6, the result determination includes: If the breakdown voltage JC4, JC5, and JC6 are all greater than 28KV / cm 2 , the packaging film is judged to be qualified; If one of the breakdown voltages JC4, JC5, and JC6 does not meet the requirement of >28KV / cm 2 , it is judged that there is a risk; If two or more of the breakdown voltages JC4, JC5, and JC6 do not meet the requirement of >28KV / cm 2 , the packaging film is judged to be unqualified.

4. The photovoltaic module encapsulation film testing method according to claim 1, characterized in that: The illumination test in step S3 includes: 2 The test sample (100) was subjected to 60KWh / m 2 of irradiation.

5. The photovoltaic module encapsulation film testing method according to claim 1 or 4, characterized in that: The reverse current overload test in step S3 includes: passing a rated current value of 1.35 times the breaking current of the junction box fuse through the test sample (100) for 2 hours.

6. The photovoltaic module encapsulation film testing method according to claim 1, characterized in that: In step S2 and step S4, the third packaging film (107) packaged in the test sample (100) is taken out by breaking the front glass (101).

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