Natural ester nanofluid as an alternative insulating liquid for transformers

Abstract

Mineral oil (MO), the conventional insulating oil used in transformers, is non newlinebiodegradable and hence a threat to the environment. Several alternatives to the newlineconventional insulating oil have been proposed, natural esters (NE) being the most newlinesuitable one. Natural esters, derived from agro-seeds and flowers, possess good newlinethermal, dielectric properties and are fully biodegradable. The present work is the newlinepreparation and characterisation of natural ester nanofluids (NENF) using insulating newlineAlumina nanofiller and comparison of its properties with that of MO, NE and mineral newlineoil nanofluid (MONF). A study on the behavior of the solid insulation and the newlinecompatibility of other materials used in transformer construction with the developed newlinenanofluid is done. The biodegradability concern of the developed nanofluid is also newlineaddressed in the present work. newlineNENF and MONF of 0.002, 0.01, 0.02, 0.04 and 0.1 wt% are prepared using a newlinetwo-step preparation method. Stability analysis of the prepared nanofluid is done newlineby UV-Vis spectroscopy, turbidity meter measurement and visual observation. The newlinecharacterisation of the unfilled and nanofilled oils shows that the AC breakdown newlinevoltage of 0.02 wt.% NENF is 27.8% higher than unfilled MO. Also, results show a newlinehigher thermal conductivity of NENF when compared to MO, NE and MONF. The newlineflash point and fire point of NE and NENF are almost twice that of MO and MONF, newlinesubstantiating its fire safety properties. newlineThe insulating oil in a transformer comes in contact with different materials used newlinein transformer construction, of which cellulose insulation is significant because of newlineits insulating properties. newline