Abstract:
In most cases, The electrical insulation of the transformer oil is exposed to different internal problems, such as short circuit , over voltage, over load, over excitation and etcetera. The insulation of transformer is sever decreased into minimum value, that is unacceptable. This requires some treatments of oil liquid ,such as refining or replacing the old oil, which is a very expensive process. In this paper, The old oil is enhanced with nanoparticles (NPs) for reusing in the power transformer again. The NPs enhance the insulation, physical and chemical properties of transformer oil. The breakdown voltage(BDV) and the dissipation factor (DF) are tested for old oil and after addition the NPs according to IEC standard methods. The NPs are many types, Titanium oxide (TiO2) is one of them, which is used in this research. NPs reduce the effect of moisture as it absorb and form hydroxyl groups around. Also, reduce the effect of dissolved carbonate in oil without harmful effects. A comparative study is conducted to identify the effects of using NPs in transformer oil to ensure their effect on electrical insulation, Also to be used again. The results show that adding small amount of TiO2 to transformer oil improves its breakdown strength as well as dissipation factor.
