Photovoltaic module integrated aging test method

Abstract

The application discloses a photovoltaic module comprehensive aging test method, comprising: pre-test; PID+UV comprehensive aging test, placing the experimental sample completing the pre-test in ultraviolet light to perform PID test; post-test; result processing, comparing the pre-test result with the post-test result, and analyzing the performance of the experimental sample. By synchronously applying ultraviolet light in the PID test process, the influence of PIDp on the test result is excluded, so that the failure mechanism of PID and UV cooperative degradation in actual outdoor operation is more truly reproduced; meanwhile, the performance of the experimental sample before and after the PID+UV comprehensive aging test is compared, and the change of the sample performance in the actual operation process is analyzed.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module technology, and more specifically, to a comprehensive aging test method for photovoltaic modules. Background Technology

[0002] In actual power plant operation, a potential difference exists between photovoltaic modules and the ground, which is particularly significant in the vicinity of the inverter. TOPCon technology, due to the increased sensitivity of cells to ultraviolet light, is susceptible to UV-induced degradation. Under the combined effects of long-term external voltage, humid and hot environments, and ultraviolet radiation, the module power continuously decreases, severely impacting the efficiency and lifespan of the photovoltaic system. Existing UV testing and PID testing are independent tests that need to be conducted separately. Although each test is important, they cannot simulate the multi-factor interaction in outdoor environments and are insufficient to expose material defects, such as UV-induced cracks followed by accelerated delamination under humid and hot conditions, and PID causing electrical performance degradation.

[0003] With the large-scale application of photovoltaic systems, system voltages are constantly increasing. Typically, 20–22 modules are connected in series to meet the inverter's maximum power point tracking (MPPT) operating voltage, resulting in higher open-circuit and operating voltages. The high potential difference between the cells and the frame (ground) easily causes charge to accumulate on the passivation layer surface, inducing polarization potential-induced degradation (PID-p). According to IEC 61215-2:2021, when power degradation exceeds 5% after a PID test, a final stability test with a cumulative 2 kWh / m² UV irradiation is required to eliminate PID-p interference. In actual testing, many modules exhibit excessive degradation after the PID test, and power can only recover to within 5% after UV irradiation, leading to a longer testing process and increased testing and labor costs.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a comprehensive aging test method for photovoltaic modules, which improves test efficiency while eliminating PID-p interference.

[0006] This invention is implemented as follows: In a first aspect, the present invention provides a comprehensive aging test method for photovoltaic modules, comprising: Before the experiment, at least one of the following tests was performed on the experimental sample that had achieved initial stability: first appearance inspection, first maximum power test, first electroluminescence test, and first wet leakage test. The maximum power measured in the first maximum power test was recorded as P1. The PID+UV integrated aging test involves placing the experimental samples that have completed the tests before the experiment under ultraviolet light conditions for PID testing. Post-test testing involves performing at least one of the following on the experimental samples that have completed the PID+UV comprehensive aging test: a second appearance inspection, a second maximum power test, a second electroluminescence test, and a second wet leakage test. The maximum power measured in the second maximum power test is recorded as P2. The pre-test and post-test tests include at least one of the same tests. Results processing involves comparing the results of pre-experiment and post-experiment tests to analyze the performance of the experimental samples.

[0007] In an optional implementation, the initial stabilization is performed in accordance with the requirements of 4.19.5 in IEC 61215:2021; And / or, the first visual inspection and / or the second visual inspection in accordance with IEC 61215 2: MQT01 will be conducted in 2021; And / or, the first wet leakage current test and / or the second wet leakage current test shall be performed in accordance with MQT 15 of IEC 61215; And / or, the first maximum power test and / or the second maximum power test according to IEC 61215 2: MQT19 in 2021.

[0008] In an optional implementation, the experimental samples consist of four or more pieces.

[0009] In an optional implementation, the experimental sample is selected from a single-glass module or a double-glass module.

[0010] In an optional implementation, the PID+UV integrated aging test includes: applying a bias voltage between the battery busbar and the frame of the test sample, and connecting a micro inverter between the positive and negative output terminals of the component.

[0011] In an optional implementation, a positive bias voltage is applied between the battery busbar and the frame of at least two experimental samples; a negative bias voltage is applied between the battery busbar and the frame of at least two experimental samples.

[0012] In an optional implementation, the positive bias voltage is +1500V to +1000V; And / or, the negative bias voltage is -1500V to -1000V.

[0013] In an optional implementation, the PID+UV integrated aging test time is 80-120 hours.

[0014] In an optional implementation, the temperature of the PID+UV integrated aging test is 50-70℃, the relative humidity is 80-90%RH, and the UV intensity is 150±10w / ㎡.

[0015] In an optional implementation, the result processing includes at least one of ac: a. When the power attenuation exceeds the first preset value, the corresponding experimental sample is deemed unqualified; where power attenuation = (P2) P1) / P1*100%; b. If the electrical insulation resistance value obtained from the second wet leakage test is less than the second preset value, the corresponding experimental sample is unqualified; c. Compare the changes in the images of the first and second electroluminescence tests, identify and count the size and number of cracks and fragments in the images, and determine the changes in the defects of the experimental samples before and after the PID+UV comprehensive aging test. d. Compare the results of the first and / or second visual inspections to determine the changes in the appearance of the corresponding experimental samples; e. Compare the (P2) values ​​of the two experimental samples. P1) / P1*100% value, (P2) The test sample with a smaller P1) / P1*100% value has better anti-aging performance.

[0016] The present invention has the following beneficial effects: This application accelerates the aging of photovoltaic modules under the coupled effect of potential-induced degradation stress and ultraviolet radiation stress by simultaneously applying ultraviolet light during the PID test, thus eliminating the PID problem. The impact of p on the test results allows for a more realistic and rigorous reproduction of the failure mechanism of PID and UV synergistic degradation during actual outdoor operation. At the same time, by using consistent multi-dimensional test items such as maximum power, EL, and wet leakage current for comparative analysis, it is possible to accurately identify and quantify the specific performance degradation modes caused by this composite stress, such as decreased anti-PID capability, interface delamination or accelerated ion migration induced by UV aging of encapsulation materials, etc., thereby improving the effectiveness of aging test results in assessing the long-term reliability of components. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of the application; Figure 2 These are electroluminescence images of the sample before and after testing in Example 1; Figure 3The images show the electroluminescence of the sample before and after testing in Comparative Example 1. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0020] This invention provides a comprehensive aging test method for photovoltaic modules, comprising: Before the experiment, at least one of the following tests was performed on the experimental sample that had achieved initial stability: first appearance inspection, first maximum power test, first electroluminescence test, and first wet leakage test. The maximum power measured in the first maximum power test was recorded as P1. The PID+UV integrated aging test involves placing the experimental samples that have completed the tests before the experiment under ultraviolet light conditions for PID testing. Post-test testing involves performing at least one of the following on the experimental samples that have completed the PID+UV comprehensive aging test: a second appearance inspection, a second maximum power test, a second electroluminescence test, and a second wet leakage test. The maximum power measured in the second maximum power test is recorded as P2. The pre-test and post-test tests include at least one of the same tests. Results processing involves comparing the results of pre-experiment and post-experiment tests to analyze the performance of the experimental samples.

[0021] This application accelerates the aging of photovoltaic modules under the coupled effect of potential-induced degradation stress and ultraviolet radiation stress by simultaneously applying ultraviolet light during the PID test, thus eliminating the PID problem. The impact of p on the test results allows for a more realistic and rigorous reproduction of the failure mechanism of PID and UV synergistic degradation during actual outdoor operation. Simultaneously, by employing consistent multi-dimensional testing items such as maximum power, EL, and wet leakage current for comparative analysis, specific performance degradation modes caused by this composite stress can be accurately identified and quantified, such as decreased PID resistance, interface delamination induced by UV aging of the encapsulation material, or accelerated ion migration. This enhances the effectiveness of aging test results in assessing the long-term reliability of components, while simplifying the testing process and improving testing efficiency.

[0022] In an optional implementation, the initial stabilization is performed in accordance with the requirements of 4.19.5 in IEC 61215:2021; And / or, the first visual inspection and / or the second visual inspection in accordance with IEC 61215 2: MQT01 will be conducted in 2021; And / or, the first wet leakage current test and / or the second wet leakage current test shall be performed in accordance with MQT 15 of IEC 61215; And / or, the first maximum power test and / or the second maximum power test according to IEC 61215 2: MQT19 will be held in 2021.

[0023] In an optional implementation, the experimental samples consist of four or more pieces, which improves the statistical representativeness and robustness of the test results and reduces the interference of individual differences or accidental defects of a single sample on the overall aging assessment conclusion.

[0024] In an optional implementation, the experimental samples are selected from single-glass modules or double-glass modules, which supports comparative evaluation of the differentiated responses of modules with different packaging structures under PID+UV composite stress.

[0025] In an optional implementation, the PID+UV integrated aging test includes: applying a bias voltage between the battery busbar and the frame of the experimental sample, and connecting a micro-inverter between the positive and negative output terminals of the module to better reflect actual power plant operation. This ensures that the module is in a real operating state (load-bearing) during the PID test, making the internal electric field distribution, carrier behavior, and interface ion migration process closer to actual operating conditions, thus enhancing the engineering authenticity of the aging mechanism.

[0026] In an optional implementation, a positive bias voltage is applied between the battery busbar and the frame of at least two experimental samples; a negative bias voltage is applied between the battery busbar and the frame of at least two experimental samples, so as to achieve synchronous capture of the asymmetric degradation behavior of photovoltaic modules under positive / negative polarity PID stress, which can reflect the reliability differences of the modules under different system grounding methods (such as negative grounding or positive grounding).

[0027] In an optional implementation, the positive bias voltage is +1500V to +1000V; And / or, the negative bias voltage is -1500V to -1000V.

[0028] It covers the typical operating bias range of current high-voltage photovoltaic systems, ensuring that the test conditions are consistent with the harsh electrical environment of actual power plants.

[0029] In an optional implementation, the PID+UV integrated aging test time is 80-120 hours, achieving a balance between accelerated aging and testing efficiency while ensuring the full effect of UV high temperature and high humidity conditions.

[0030] In an optional implementation, the PID+UV integrated aging test is conducted at a temperature of 50-70℃, a relative humidity of 80-90%RH, and a UV intensity of 150±10w / ㎡. This constructs a high-temperature, high-humidity, and high-UV synergistic environment, enhancing the coupling effect among water vapor permeability, ion mobility, and UV-induced material degradation, thereby stimulating PID-related failure and UV-driven aging.

[0031] In an optional implementation, the result processing includes at least one of ae: a. When the power attenuation exceeds the first preset value, the corresponding experimental sample is deemed unqualified; where power attenuation = (P2) P1) / P1*100%; Power attenuation directly reflects the degree of substantial damage to the photoelectric conversion capability of the component caused by PID+UV composite aging. The first preset value can be selected according to the actual situation, for example, it can be 5%. b. When the electrical insulation resistance value obtained from the second wet leakage test is less than the second preset value, the corresponding experimental sample is unqualified. As the electrical insulation resistance increases, the risk of leakage current caused by the intrusion of water vapor due to the aggravation of ultraviolet aging or the enrichment of interface ions induced by PID increases. Therefore, the second preset value should not be too high, for example, it can be (40 / module area) MΩ. c. Compare the changes in the images of the first and second electroluminescence tests, identify and count the size and number of cracks and fragments in the images, and determine the changes in the defects of the experimental samples before and after the PID+UV comprehensive aging test. d. Compare the results of the first and / or second visual inspections to determine the changes in the appearance of the corresponding experimental samples; e. Compare the (P2) values ​​of the two experimental samples. P1) / P1*100% value, (P2) The test sample with a smaller P1) / P1*100% value has better anti-aging performance.

[0032] In an optional implementation, the photovoltaic module PID+UV integrated testing method is as follows: Figure 1 As shown, it includes: Step S1: Obtain the test sample assembly Four photovoltaic modules of the same specifications and model were selected as test samples.

[0033] Step S2, Initial Stability The four test samples were initially stabilized according to the requirements of 4.19.5 in IEC 61215:2021.

[0034] Step S3, Pre-experiment testing The four initially stabilized test samples underwent the first appearance inspection, the first maximum power test, the first electroluminescence test, and the first wet leakage test. The maximum power measured in the first maximum power test was recorded as P1.

[0035] Step S4: PID+UV Integrated Aging Test Before and after the test, clean the surface of the test samples to remove any moisture. Then, place the photovoltaic modules in an ultraviolet high temperature and high humidity environment chamber with the front of the single-glass module facing up and the back of the double-glass module facing up.

[0036] A micro-inverter is connected between the positive and negative terminals of the photovoltaic module to simulate the normal operation of the module; the positive and negative leads of the photovoltaic module are connected to the bias power supply.

[0037] The ambient temperature in the test chamber was 50-70℃, the relative humidity was 80-90%RH, and the irradiance was 150±10w / ㎡. When the temperature of the photovoltaic modules reached the set value, the bias voltage was turned on. Two photovoltaic modules were set to positive bias and two photovoltaic modules were set to negative bias. The test time was 96 hours.

[0038] In this test sample, a positive maximum rated system voltage (+1500V to +1000V) was applied to two of the components, and a negative maximum rated system voltage was applied to the remaining two components. 1500V to 1000V).

[0039] Step S5, Post-test Testing The test samples after the PID+UV comprehensive aging test were subjected to a second appearance inspection, a second maximum power test, a second electroluminescence test, and a second wet leakage test. The maximum power measured in the second maximum power test was recorded as P2.

[0040] Step S6: Result Processing a. When the power attenuation exceeds the first preset value, the corresponding experimental sample is deemed unqualified; where power attenuation = (P2) P1) / P1*100%; b. If the electrical insulation resistance value obtained from the second wet leakage test is less than the second preset value, the corresponding experimental sample is unqualified; c. Compare the changes in the images of the first and second electroluminescence tests, identify and count the size and number of cracks and fragments in the images, and determine the changes in the defects of the experimental samples before and after the PID+UV comprehensive aging test. d. Compare the results of the first and / or second visual inspections to determine the changes in the appearance of the corresponding experimental samples; e. Compare the (P2) values ​​of the two experimental samples. P1) / P1*100% value, (P2) The test sample with a smaller P1) / P1*100% value has better anti-aging performance.

[0041] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0042] Example 1 A comprehensive PID+UV testing method for photovoltaic modules, such as Figure 1 As shown, the method includes: Step S1: Obtain the test sample assembly Photovoltaic modules were selected as the test samples.

[0043] Step S2, Initial Stability The test samples were initially stabilized in accordance with the requirements of 4.19.5 in IEC 61215:2021.

[0044] Step S3, Pre-experiment testing After initial stabilization, the test sample underwent the first appearance inspection, the first maximum power test, the first electroluminescence test, and the first wet leakage test. The maximum power measured in the first maximum power test was recorded as P1.

[0045] Step S4: PID+UV Integrated Aging Test Before and after the test, clean the surface of the test sample to remove any moisture. Then, place the photovoltaic module in an ultraviolet high temperature and high humidity environment chamber with the front facing up.

[0046] A micro-inverter was connected between the positive and negative terminals of the photovoltaic module to simulate the normal operation of the module; the positive and negative leads of the test sample were connected to a bias power supply.

[0047] The ambient temperature was 60℃±2℃, the relative humidity was 85%RH±5%RH, and the irradiation intensity was 150±10w / ㎡. When the temperature of the test sample reached the set value, the bias voltage was turned on. Two test samples were set to positive bias voltage and two test samples were set to negative bias voltage. The test time was 96 hours.

[0048] Among them, the negative maximum rated system voltage is applied to the test sample ( 1500V).

[0049] Step S5, Post-test Testing The test samples after the PID+UV comprehensive aging test were subjected to a second appearance inspection, a second maximum power test, a second electroluminescence test, and a second wet leakage test. The maximum power measured in the second maximum power test was recorded as P2.

[0050] Step S6: Result Processing Electroluminescence images of one of the samples before and after testing are as follows: Figure 2 As shown in Table 1, the results of the pre-test and post-test are as follows.

[0051] Table 1

[0052] Comparative Example 1 Two photovoltaic modules of the same batch and specifications as the test samples in Example 1 were selected as test samples and tested in accordance with IEC 61215-2:2021.

[0053] The test results in this comparative example are shown in Table 2. One sample's electroluminescence images before and after testing are shown below. Figure 3 As shown.

[0054] Table 2

[0055] The detection results in the above embodiments and comparative examples deviated from those in Comparative Example 1 by less than 0.3%, showing no significant difference. Furthermore, the test process was simplified and the test efficiency was improved.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A comprehensive aging test method for photovoltaic modules, characterized in that, include: Before the experiment, at least one of the following tests was performed on the experimental sample that had achieved initial stability: first appearance inspection, first maximum power test, first electroluminescence test, and first wet leakage test. The maximum power measured in the first maximum power test was recorded as P1. The PID+UV integrated aging test involves placing the experimental samples that have completed the tests before the experiment under ultraviolet light conditions for PID testing. Post-test testing involves performing at least one of the following on the experimental samples that have completed the PID+UV comprehensive aging test: a second appearance inspection, a second maximum power test, a second electroluminescence test, and a second wet leakage test. The maximum power measured in the second maximum power test is recorded as P2. The pre-test and post-test tests include at least one of the same tests. Results processing involves comparing the results of pre-experiment and post-experiment tests to analyze the performance of the experimental samples.

2. The photovoltaic module comprehensive aging test method according to claim 1, characterized in that, The initial stabilization was performed in accordance with the requirements of 4.19.5 in IEC 61215:2021; And / or, the first visual inspection and / or the second visual inspection in accordance with IEC 61215 2: MQT01 will be conducted in 2021; And / or, the first wet leakage current test and / or the second wet leakage current test shall be performed in accordance with MQT 15 of IEC 61215; And / or, the first maximum power test and / or the second maximum power test according to IEC 61215 2: MQT19 will be held in 2021.

3. The photovoltaic module comprehensive aging test method according to claim 1, characterized in that, The experimental samples consisted of more than four pieces.

4. The photovoltaic module comprehensive aging test method according to claim 1, characterized in that, The experimental samples were selected from single-glass modules or double-glass modules.

5. The photovoltaic module comprehensive aging test method according to claim 1, characterized in that, The PID+UV integrated aging test includes: applying a bias voltage between the battery busbar and the frame of the experimental sample, and connecting a micro inverter between the positive and negative output terminals of the component.

6. The photovoltaic module comprehensive aging test method according to claim 5, characterized in that, A positive bias voltage is applied between the battery busbar and the frame of at least two experimental samples; a negative bias voltage is applied between the battery busbar and the frame of at least two experimental samples.

7. The photovoltaic module comprehensive aging test method according to claim 6, characterized in that, The positive bias voltage is +1500V to +1000V; And / or, the negative bias voltage is -1500V to -1000V.

8. The photovoltaic module comprehensive aging test method according to claim 1, characterized in that, The PID+UV integrated aging test time is 80-120 hours.

9. The photovoltaic module comprehensive aging test method according to claim 1, characterized in that, The PID+UV integrated aging test was conducted at a temperature of 50-70℃, a relative humidity of 80-90%RH, and a UV intensity of 150±10w / ㎡.

10. The photovoltaic module comprehensive aging test method according to claim 1, characterized in that, The result processing includes at least one of ae: a. When the power attenuation exceeds the first preset value, the corresponding experimental sample is deemed unqualified; where power attenuation = (P2) P1) / P1*100%; b. If the electrical insulation resistance value obtained from the second wet leakage test is less than the second preset value, the corresponding experimental sample is unqualified; c. Compare the changes in the images of the first and second electroluminescence tests, identify and count the size and number of cracks and fragments in the images, and determine the changes in the defects of the experimental samples before and after the PID+UV comprehensive aging test. d. Compare the results of the first and / or second visual inspections to determine the changes in the appearance of the corresponding experimental samples; e. Compare the (P2) values ​​of the two experimental samples. P1) / P1*100% value, (P2) The test sample with a smaller P1) / P1*100% value has better anti-aging performance.

Images