Behavior of Nanoparticles in Service Transformer Oils and their Performance on Laboratory Ageing

Abstract

The transformer is the most critical apparatus in the electric power network. Reliable operation of it is of foremost concern for a proficient power supply. Therefore, it is vital to safeguard the transformer so that it functions at its highest capacity. In order to achieve it, an improvement in the insulation system is necessary, as the majority of faults in transformers are due to the malfunctioning of the insulation system. Petroleum-based oils are extensively used as insulating liquids in transformers. The latterly evolved field of nanotechnology has encouraged studies on Nanofluids (NFs), which are suitable as liquid insulators. In spite of the advantages of NFs in electrical and thermal behavior compared to their base fluids, further studies are needed to establish their long-standing performances as liquid insulators. In this study, three mineral oil samples, new, mid-aged, and extensively aged, were taken. Nanofluids of 0.02% Al2O3 and 0.02% SiO2 of these oils were prepared. The base fluids and nanofluids were characterized by interfacial tension, acidity, dielectric dissipation factor, resistivity, and electric strength. The nanofluids prepared were subjected to laboratory thermal ageing in the presence of copper and kraft paper for 64 hours at 150 °C. The unaged and laboratory-aged nanofluids were characterized for acidity, Interfacial Tension (IFT), Specific Resistance (SR), Tan Delta (TD), and Dielectric Strength (BDV). It was found through this work that the addition of nanoparticles upgraded the properties of oil samples. The long-term applicability and permanence of nanofluids might depend on catalytic effects. These catalytic effects are derived from the internal assembly materials of the transformer.