TESTING PV CONNECTOR DATA

The paper presents the reliability study on field-aged photovoltaic connectors of different makes, collected from solar PV plants situated in different regions across India, each characterized by diverse climatic conditions having an operational life of two to ten years. A series of tests conforming to IEC 62852 incorporating C-AST is conducted on connectors encompassing both field-aged and control samples. Thereafter these samples and new field-aged samples underwent SEM for further analysis. The objective of these investigations was to elucidate the mechanisms of aging and evaluate the reliability of connectors, identify failure modes, potential hazards, and changes in electrical and mechanical performance because of longstanding exposure to environmental and operational stresses. The on-site field survey and testing reveal lack of awareness of the workmanship and maintenance of connectors. Samples having less than six years of operational life exhibit low contact resistance and remain relatively stable after undergoing C-AST. However, samples with operational life of six years or more from extreme climatic regions exhibited a high contact resistance in a nonlinear pattern beyond the permissible limits with values of contact resistance drastically. In SEM analysis, corrosion and fretting was observed on connectors which had shown high contact resistance with marginal polymer (outer insulation casing) deterioration.