Research on the Corrosion Mechanism and Performance Degradation of Photovoltaic Connectors in Marine Environments

Offshore photovoltaic systems pose severe challenges to the performance of photovoltaic connectors in the high salt spray environment of the ocean. This paper systematically studies the Galvanic corrosion mechanism and electrical performance degradation law of two common conductive materials, namely silver-plated copper and tin-plated copper, in the inner core of photovoltaic connectors. By constructing a three-dimensional Galvanic corrosion kinetics model and combining it with a 600-hour accelerated corrosion simulation, it was found that the synergistic effect of CI<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> and O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> significantly exacerbated the galvanic corrosion at the defects of the metal coating. The contact resistance of tin-plated copper increases due to the deposition of tin oxidation products (SnCl<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>). Silver-plated copper shows a passive film protection effect in the complete coating area. The deposition thickness of corrosion products is relatively thin, and its passive stability is better than that of tin-plated copper. The simulation results show that the contact resistances of tin-plated copper and silver-plated copper conductors increase by 79.8 milliohm and 23.5 milliohm respectively, thereby causing overheating and even arc hazards. This research provides theoretical support for the optimal selection and life prediction of photovoltaic connectors in offshore photovoltaic systems.