Titania-based transformer nanofluid: a study on the synthesis for enhanced breakdown strength and its humidity ageing

Researches on the transformer oil-based nanofluids to determine its suitability for replacing the conventional liquid insulation has been consistently happening for more than a decade. Yet, to prepare an optimum blend of transformer oil-based nanofluid with the stability compliance and superior breakdown (BD) characteristics is still a key issue to be addressed. So to achieve the higher BD voltages (BDVs) with good stability, the nanoparticle and surfactant weights dispersed in the oil should be optimised to at least possible critical levels. In this work, dielectric BD characteristic of mineral oil dispersed with TiO₂ nanoparticle and surfactant cetyl trimethyl ammonium bromide (CTAB) is been studied with the applied AC and DC high voltages, which is termed as titania-based transformer nanofluid (TTNF) for this study. Series of TTNF samples were synthesised with different weights of TiO₂ nanoparticle and CTAB, and the partial discharge inception voltage, AC and DC BDV were experimented to ascertain the optimum concentration level. Results show that the AC and DC BDV enhanced up to 36.23 and 43.07%, respectively, for the TTNF prepared with 0.00562 wt% of TiO₂ and its 1% weight of CTAB, which was stable for around eight weeks.