Experimental investigations on properties of additives mixed natural esters based liquid insulating medium for power system transformer

Abstract

newline Transformers are one among the key equipment of the electrical power system transmission and distribution. Most of the transformers are filled with the petroleum based mineral oil which is used as an insulating fluid for its properties of insulation and cooling nature. The reliability and longevity of transformers are mainly depends on the insulation medium. The performance of insulating oil in an insulation medium depends upon the physical, chemical and electrical properties which can affects the performance of the transformer. To meet the rise in power demands for industrial applications and electricity in rural areas, installation of transformer is increasing which is strongly associated in increasing the demand of mineral oil. But mineral oil is toxic, slow in biodegradation and has shortage of resource now-a-days. These factors have encouraged the search of alternate environmental friendly fluid such as natural esters for the replacement of mineral oil. The natural ester based fluids such as corn oil, soybean oil, sunflower oil, rice bran oil, mustard oil, castor oil and punna oil are considered in this work to identify the suitable transformer insulating medium.The overall objective of this thesis is to study the performance of natural ester based fluid on full scale to identify the suitable replacement fluid for transformer application. This research work focuses to investigate the properties like breakdown voltage, interfacial tension, flash point, fire point, acidity, water content and viscosity for various natural ester based fluid samples which are environmental friendly and biodegradable in nature.