Investigations on environmental friendly non edible ester oils performance for transformers

Abstract

Natural esters have emerged as a viable and sustainable alternate for liquid insulation in power transformers. However, the natural esters currently used for transformer applications are extracted from edible sources, leading to concerns about their impact on the food supply. In order to overcome this issue, studies on the dielectric properties of non-edible natural esters have received a lot of attention in industries as alternative dielectric liquids for power transformers. In this research work, non-edible natural esters, namely Jatropha oil, Karanja oil, and Mahua oil are taken for analysis. Cellulose materials are impregnated with these oil samples, further, the samples are aged at 130oC up to 28 days. Different dielectric, mechanical, physical and chemical parameters are measured and analyzed after every 7 days of aging. When comparing the results, karanja oil performed better than others. Liquid insulation serves as both a coolant and insulating medium in numerous high voltage devices, effectively separating conducting elements. Typically, petroleum-derived mineral oil employed as a liquid dielectric in applications like oil bushings and transformers. However, recent studies have concentrated on developing alternative liquid insulation options using natural esters derived from seeds and plants. One primary challenge associated with natural esters are their increased viscosity and pour point, and it affects the cooling behaviour of the insulation liquid. Hence, this research focuses on non edible natural esters, namely Jatropha oil, Karanja oil, and Mahua oil samples. These oil samples are subjected to treatment by ultrasonic waves with an ultrasonic power of 500 W and frequencies of 20 kHz, 25 kHz, and 30 kHz for varying durations (30 min, 60 min, 90 min, and 120 min) to reduce viscosity and pour point. newline