The high efficiency and reliability of photovoltaic modules during the life cycle are two important connotations of the quality of photovoltaic power generation. For a long time, Trina Solar has started from the source of the quality of photovoltaic modules - key materials, taking the environmental durability of materials as the assessment object, selecting materials with high transmission, high resistance and high weather resistance, and paying attention to the performance of photovoltaic modules throughout the life cycle situation.
01
Photovoltaic ribbon
Photovoltaic Welding Strip
Photovoltaic ribbon (tin-coated copper ribbon): It is mainly divided into interconnection strip and bus strip. Interconnecting strips are mainly used in the connection between photovoltaic module cells to conduct electricity and collect cell current; inside the junction box.
Welding strip resistance: It is mainly determined by the size of the welding strip itself and the material of the copper substrate.
Failure due to ribbon:
①Virtual soldering and over-soldering: Too low soldering temperature, uneven application of flux and many other reasons can lead to false soldering, while too high soldering temperature or too long soldering time can lead to over-soldering. False welding will cause the welding tape to separate from the cell during the actual use of the module, and the power of the module will be attenuated.
② Welding ribbon offset: Due to the abnormal positioning of the welding machine, the contact between the welding ribbon and the battery area is reduced, and delamination, power attenuation and other phenomena occur. With the increase of the busbars of the battery, the width (diameter) of the welding strip is getting narrower and narrower, which requires higher positioning accuracy of the welding machine.
02
Junction Box
Photovoltaic Junction Boxes
The function of the junction box: It is installed on the photovoltaic module to transmit current. During normal use, it has appropriate protection to prevent the influence of the external environment and the possible damage caused by touching the live body inside the junction box.
Performance requirements: While having good electrical performance, the design and size of the junction box must meet the requirements of the use environment, including: electrical, mechanical, heat resistance, corrosion resistance and weather resistance. At the same time, it must not cause harm to users and the environment.
Smart junction box: The internal circuit of the traditional module junction box is composed of bus bars and diodes, and there are no other electronic components such as electronic circuit boards. The MPPT tracking of photovoltaic systems is realized by inverters or controllers. The smart component is that the printed circuit board or related electronic components are integrated in the component and integrated inside the junction box to achieve component-level optimization, detection and control. Smart components enable the transition from passive to active control.
03
Aluminum alloy frame
Aluminum Alloy frame
The role of the aluminum frame: First, to protect the edge of the glass; Second, aluminum alloy combined with silica gel to strengthen the sealing performance of the module; Third, greatly improve the overall mechanical strength of the module; Fourth, to facilitate the installation and transportation of the module; Fourth, to carry the module The link carrier with the bracket can achieve the best anti-load capacity through fixing, from unit fixing to integration, improving the mechanical capacity of the power station system.
At present, research on the characteristics of aluminum frame materials 6063-T5 and 6005-T6: T5 represents solution treatment plus incomplete artificial aging / T6 represents solution treatment plus complete artificial aging.
①Solid solution treatment: It refers to the heat treatment process in which the alloy is heated to a high temperature single-phase region and maintained at a constant temperature, so that the excess phase is fully dissolved into the solid solution and then rapidly cooled to obtain a supersaturated solid solution.
②Incomplete artificial aging: Use a relatively low aging temperature or a short holding time to obtain excellent comprehensive mechanical properties, that is, to obtain relatively high strength, good plasticity and toughness, but the corrosion resistance may be relatively low.
③Complete artificial aging: Using a higher aging temperature and a longer holding time, the maximum hardness and the highest tensile strength are obtained, but the elongation is low.
In the production process, the T6 type aluminum alloy is formed by high temperature extrusion, and the state of artificial aging after solution heat treatment (quenching) is water cooling, while the T5 type aluminum alloy is cooled during the high temperature extrusion forming process, and then artificially aged is air cooling. Compared with the two cooling methods, the hardness of the profile after T6 water cooling will be higher, but the plasticity and toughness of the profile will be affected.
At present, my country's photovoltaic industry ranks among the top in the world in terms of manufacturing scale, industrialization technology level, application market expansion, and industrial system construction. However, the photovoltaic industry is developing rapidly, especially the technological progress is extremely rapid, and the industry is in a period of rapid change. High-quality auxiliary materials for photovoltaic modules are an important guarantee for the high efficiency and reliability of modules, and should be paid more attention by the industry. At the same time, how to achieve high efficiency and low cost on the premise of ensuring the life and reliability of photovoltaic modules, and the cost reduction and efficiency increase of auxiliary materials are also crucial.