Photovoltaic module environment test method

Abstract

The invention discloses a photovoltaic module environment test method, which relates to the technical field of photovoltaic module test, and comprises the steps of S1, sample preparation and initial performance test, S2, environment test and post-test performance test, and S3, data processing, result judgment and power correction. Wherein in the step S3, the light transmittance retention rate of the front light-transmitting plate is calculated according to the test result, and whether the test result needs to be corrected or not is determined according to the light transmittance retention rate. The test method comprises a method for correcting the power in the test result, and the real power attenuation condition of the photovoltaic module after the environment test is obtained through power correction calculation. According to the testing method, the defects of a traditional standard testing method can be overcome, the stability and reliability of all components and packaging materials of a photovoltaic module product under various testing environment conditions are truly reflected, then potential manufacturing defects and problems are found, and the purpose of improving the overall quality and performance of the photovoltaic module is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaic component testing, and in particular relates to a photovoltaic component environmental test method. Background Art

[0002] At present, when photovoltaic manufacturers update new materials or improve and upgrade products, in order to verify the process reliability of materials or new products, they need to conduct a series of environmental tests to ensure that the life of photovoltaic modules can reach more than 25 years. Among them, the damp heat test (DH), thermal cycle test, and humidity test are important aging tests, which can systematically evaluate and analyze the environmental resistance of various components and packaging materials of photovoltaic module products, and then improve them to enhance the overall performance of the product.

[0003] In the prior art, since most environmental tests on photovoltaic modules are simulated tests performed in laboratories using environmental test chambers, water stains or watermarks will appear on the glass surface of the photovoltaic modules after the environmental tests. The ordinary testing process cannot determine whether the changes in the glass surface affect the module test results and the extent of the impact on the module test results.

[0004] Therefore, it is necessary to provide a method for effectively identifying the extent of the impact of glass on component performance after environmental testing and a method for correcting it. Summary of the invention

[0005] The purpose of the present invention is to provide a photovoltaic module environmental test method to solve the above technical problems existing in the prior art.

[0006] To achieve the above object, the present invention provides the following solution: a photovoltaic module environmental test method, comprising the following steps:

[0007] Step S1, sample preparation and initial performance test: select a front light-transmitting plate of the same material as the sample component to be tested, and perform an initial light transmittance test on the front light-transmitting plate, and record the test result as T1; use the front light-transmitting plate to make a control sample component, and an isolation layer is provided between the front light-transmitting plate and the front packaging film of the control sample component; perform an initial performance test on the sample component to be tested, and obtain an initial test result;

[0008] Step S2, environmental test and post-test performance test: perform environmental test on the sample assembly to be tested and the control sample assembly; remove the frame of the control sample assembly after the environmental test, take out the front light-transmitting plate and perform a post-test transmittance test on it, and record the test result as T2; perform a post-test performance test on the sample assembly to obtain a post-test test result;

[0009] Step S3, data processing, result determination and power correction: obtain the environmental test results of the sample assembly to be tested based on the post-test results and the initial test results, and calculate the post-test transmittance retention rate Tr = T2 / T1×100; when the transmittance retention rate is lower than the first threshold, the test result needs to be corrected; when the transmittance retention rate is lower than the second threshold, it is considered that the front light-transmitting plate has too much influence on the test result in this test, and the environmental test needs to be repeated.

[0010] Preferably, the initial performance test and the post-test performance test both include an electrical performance test, an electroluminescence EL test and an initial wet leakage test, and the test results of the two performance tests are recorded as: P1, EL1, E1 and P2, EL2, E2, respectively.

[0011] Preferably, the first threshold is 98%, and the second threshold is 90%;

[0012] When the transmittance retention rate Tr ≥ 98%, P2 is considered to be the component power certification value after environmental testing;

[0013] When 90%≤transmittance retention rate Tr<98%, the component power needs to be corrected;

[0014] When the transmittance retention rate Tr is less than 90%, it is considered that the test glass has too great an impact on the component power and needs to be repeated.

[0015] Preferably, the method for correcting component power includes:

[0016] The theoretical short-circuit current Isc' is calculated by K*T1, and the theoretical power P2' after the environmental test of the photovoltaic module is obtained according to the power calculation formula P=Voc*Isc'*FF, and then the actual attenuation of the sample module to be tested after the environmental test is calculated as P 衰 =(P1-P2') / P1*100, P 衰 ≤5%; wherein, K is the transmittance value obtained by comparing the transmittance change of the front light-transmitting plate before and after the test, 0.96≤K≤0.98.

[0017] Preferably, the theoretical short-circuit current Isc' is calculated according to Formula 1 and Formula 2, wherein,

[0018] Formula 1 is:

[0019] Formula 2 is: I SC =J sc A;

[0020] Where:

[0021] J sc - Short-circuit current density;

[0022] S AM1.5 (λ)-AM1.5 solar irradiance;

[0023] τ(λ) – light transmittance of glass;

[0024] SR(λ) – absolute spectral response;

[0025] I SC - Short-circuit current;

[0026] A – The effective area of ​​the component.

[0027] Preferably, the environmental test results of the sample assembly to be tested obtained based on the post-test results and the initial test results also include:

[0028] Comparing the changes between EL2 and EL1, there should be no obvious cell defects;

[0029] E2×Sample component area should be ≥40GΩ*m 2 .

[0030] Preferably, the electrical performance test is performed under an air quality index of AM1.5 and a light intensity of 1000W / m 2 , and the STC standard test conditions of 25°C.

[0031] Preferably, the environmental test in step S2 includes one or more of a damp heat test, a thermal cycle test, and a humidity test.

[0032] The present invention discloses the following technical effects:

[0033] The present invention provides a method for effectively identifying the degree of influence of glass factors on component performance after environmental testing and a method for correcting the same. The degree of influence of glass factors on component performance after environmental testing is effectively identified through the transmittance retention rate r, and the real power attenuation of photovoltaic components after environmental testing is obtained by power correction calculation. The testing method of the present invention can overcome the shortcomings of traditional standard testing methods, truly reflect the stability and reliability of various components and packaging materials of photovoltaic component products under various testing environmental conditions, discover potential manufacturing defects and problems, and thus make improvements before the product is put on the market, improve the overall quality and performance of photovoltaic components, and ensure the safety and efficiency of long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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.

[0035] Figure 1 The present invention is a flow chart of the photovoltaic module environmental test method. DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] Reference Figure 1 As shown, an embodiment of the present invention provides a photovoltaic module environmental test method for effectively identifying the degree of influence of glass factors on module performance after environmental testing and proposing a correction method. The test method includes the following steps:

[0039] Step S1: Sample preparation and initial performance testing

[0040] Step S11, select a front light-transmitting plate made of the same material as the sample component to be tested, and perform an initial light transmittance test on the front light-transmitting plate, and record the test result as T1.

[0041] Step S12, using the front light-transmitting plate to make a control sample assembly, wherein an isolation layer is provided between the front light-transmitting plate and the front packaging film of the control sample assembly, and the isolation layer is used to isolate the front light-transmitting plate and the front packaging film and does not affect the transmittance of the front light-transmitting plate.

[0042] Step S13: perform an initial electrical performance test on the sample component to be tested, and record the test result as P1.

[0043] Step S14: perform an initial electroluminescence (EL) test on the sample component to be tested, and record the test result as EL1.

[0044] Step S15: perform an initial wet leakage test on the sample component to be tested, and record the test result as E1.

[0045] In a specific embodiment, the front light-transmitting plate is made of tempered glass, and the isolation layer can be made of Teflon.

[0046] In a specific embodiment, the initial electrical performance test is carried out under standard test conditions (STC), specifically, when the air quality index is AM1.5 and the light intensity is 1000W / m 2 , the electrical performance of photovoltaic modules was tested at a temperature of 25°C.

[0047] In a specific embodiment, the initial electrical performance test includes measuring the maximum output power, IV curve, open circuit voltage, open circuit voltage, maximum power point operating voltage and maximum power point operating current of the photovoltaic module.

[0048] In a specific embodiment, an EL tester is used to perform an initial electroluminescence EL test on a photovoltaic module, and the EL image is captured and analyzed by the EL tester to find internal defects of the cell, such as hidden cracks, fragments, cold solder joints or broken grids.

[0049] In a specific embodiment, according to the set test standard (such as IEC standard), under the corresponding temperature, humidity and spray washing conditions, the photovoltaic module is subjected to an initial wet leakage test by an insulation withstand voltage tester, and the data during the test are recorded, including temperature, humidity, leakage current, etc., wherein the insulation resistance value E1 should be ≥40GΩ·m 2 .

[0050] Step S2: Environmental test and post-test performance test

[0051] Step S21: Perform damp heat test, thermal cycle test or humidity test on both the sample assembly to be tested and the control sample assembly in accordance with IEC61215-2:2021 standard.

[0052] Step S22, remove the frame of the control sample assembly after the environmental test, take out the front light-transmitting plate and perform a post-test light transmittance test on it, and record the test result as T2.

[0053] Step S23, conduct a post-test electrical performance test on the sample assembly to be tested, and record the test result as P2.

[0054] Step S14, performing an electroluminescence (EL) test on the sample component to be tested, and recording the test result as EL2.

[0055] Step S25, performing a post-test wet leakage test on the sample assembly to be tested, and recording the test result as E2.

[0056] Step S3: Data processing, result determination and power correction

[0057] Step S31, obtaining the environmental test results of the sample assembly to be tested according to the post-test results and the initial test results, specifically including:

[0058] Comparing the changes between EL2 and EL1, there should be no obvious cell defects;

[0059] E2×Sample component area should be ≥40GΩ*m 2 ;

[0060] Transmittance retention rate Tr = T2 / T1×100;

[0061] When the transmittance retention rate Tr ≥ 98%, P2 is considered to be the power certification value after environmental testing;

[0062] When 90%≤transmittance retention rate Tr<98%, the component power needs to be corrected;

[0063] When the transmittance retention rate Tr is less than 90%, it is considered that the front light-transmitting plate has too great an impact on the component power in this test and needs to be repeated.

[0064] Step S32: Power correction

[0065] According to the spectral responsivity of the solar cell and the AM1.5 solar spectrum irradiance distribution, the short-circuit current density of the sample component to be tested is calculated, and the short-circuit current can be obtained by multiplying it by the effective area of ​​the battery. Taking into account the transmittance of the glass, the calculation formulas for the short-circuit current density and short-circuit current of the sample component to be tested are:

[0066] Formula 1:

[0067] Formula 2: I sc =J sc ·A

[0068] Where:

[0069] J sc - Short-circuit current density;

[0070] S AM1.5 (λ)-AM1.5 solar irradiance;

[0071] τ(λ) – light transmittance of glass;

[0072] SR(λ) – absolute spectral response;

[0073] I SC - Short-circuit current;

[0074] A – The effective area of ​​the component.

[0075] According to the test, the transmittance of the front light-transmitting plate before and after the environmental test is obtained, and the changes in the two transmittances are compared to determine that the transmittance value of the front light-transmitting plate is K, where 0.96≤K≤0.98, and the theoretical short-circuit current Isc' is calculated using K*T1. According to the power calculation formula P=Voc*Isc'*FF, the theoretical power P2' of the sample component to be tested after the environmental test is obtained, where Voc is the open circuit voltage of the sample component to be tested.

[0076] The actual attenuation of the sample assembly to be tested after the environmental test is P attenuation = (P1 - P2') / P1*100, P attenuation ≤ 5%.

[0077] The details not described in detail in the present invention are all conventional technical means known to those skilled in the art.

[0078] 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.

[0079] 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 environmental test method, characterized in that: The following steps are involved: Step S1, sample preparation and initial performance test: select a front light-transmitting plate of the same material as the sample component to be tested, and perform an initial light transmittance test on the front light-transmitting plate, and record the test result as T1; Use the front light-transmitting plate to make a control sample assembly, wherein an isolation layer is provided between the front light-transmitting plate and the front packaging film of the control sample assembly; perform an initial performance test on the sample assembly to be tested to obtain an initial test result; Step S2, environmental test and post-test performance test: perform environmental test on the sample assembly to be tested and the control sample assembly; remove the frame of the control sample assembly after the environmental test, take out the front light-transmitting plate and perform a post-test transmittance test on it, and record the test result as T2; perform a post-test performance test on the sample assembly to obtain a post-test test result; Step S3, data processing, result determination and power correction: obtain the environmental test results of the sample assembly to be tested based on the post-test results and the initial test results, and calculate the post-test transmittance retention rate Tr = T2 / T1×100; when the transmittance retention rate is lower than the first threshold, the test result needs to be corrected; when the transmittance retention rate is lower than the second threshold, it is considered that the front light-transmitting plate has too much influence on the test result in this test, and the environmental test needs to be repeated.

2. The photovoltaic module environmental test method according to claim 1, characterized in that: The initial performance test and the post-test performance test both include an electrical performance test, an electroluminescence EL test and an initial wet leakage test, and the test results of the two performance tests are recorded as: P1, EL1, E1 and P2, EL2, E2, respectively.

3. The photovoltaic module environmental test method according to claim 2, characterized in that: The first threshold is 98%, and the second threshold is 90%; When the transmittance retention rate Tr ≥ 98%, P2 is considered to be the component power certification value after environmental testing; When 90%≤transmittance retention rate Tr<98%, the component power needs to be corrected; When the transmittance retention rate Tr is less than 90%, it is considered that the test glass has too great an impact on the component power and needs to be repeated.

4. The photovoltaic module environmental test method according to claim 3, characterized in that: Methods for correcting component power include: The theoretical short-circuit current Isc' is calculated by K*T1, and the theoretical power P2' after the environmental test of the photovoltaic module is obtained according to the power calculation formula P=Voc*Isc'*FF, and then the actual attenuation of the sample module to be tested after the environmental test is calculated as P 衰 =(P1-P2') / P1*100, P 衰 ≤5%; wherein K is the transmittance value obtained by comparing the transmittance change of the front light-transmitting plate before and after the test.

5. The photovoltaic module environmental test method according to claim 4, characterized in that: The theoretical short-circuit current Isc' is calculated according to Formula 1 and Formula 2, where: Formula 1 is: Formula 2 is: I SC =J sc A; Where: J sc - Short-circuit current density; S AM1.5 (λ)-AM1.5 solar irradiance; τ(λ) – light transmittance of glass; SR(λ) – absolute spectral response; I SC - Short-circuit current; A – The effective area of ​​the component.

6. The photovoltaic module environmental test method according to claim 2, characterized in that: The environmental test results of the sample components to be tested obtained based on the post-test results and the initial test results also include: Comparing the changes between EL2 and EL1, there should be no obvious cell defects; E2×Sample component area should be ≥40GΩ*m 2 .

7. The photovoltaic module environmental test method according to claim 2, characterized in that: The electrical performance test was carried out under the conditions of an air quality index of AM1.5 and a light intensity of 1000W / m 2 , and the STC standard test conditions of 25°C.

8. The photovoltaic module environmental test method according to claim 1, characterized in that: The environmental test in step S2 includes one or more of a damp heat test, a thermal cycle test, and a humidity test.

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