A critical review on the characteristics of alternating liquid dielectrics and feasibility study on pongamia pinnata oil as liquid dielectrics

Green insulating fluids are playing a vital role in insulation design of the distribution transformers. Traditionally used mineral oil has lesser biodegradable and low fire resistant characteristics. Hence, it does not satisfy the new environmental regulation. Besides that, the availability of fossil fuels is also going to run out. These negative aspects motivate to search for an alternate insulating oil. This research has been proposed for feasibility study on non - edible pongamia pinnata oil as an alternate liquid dielectric which can be used in Distribution Transformers. The paper also reviews the alternate insulating oil, electrical, physical and chemical properties. Subsequently, Pongamia Pinnata Oil's electrical properties (Dielectric Strength, Dielectric Constant, Dielectric Dissipation Factor and Specific Resistance), chemical properties (Water content, Acidity) and physical properties (Viscosity, Flash Point, Interfacial Tension) have been estimated according ASTM and IEC for comparing the Pongaima Pinnata oil with conventional mineral oil. Alongside, solid insulating material deterioration, both in pongamia pinnata oil and mineral oil, using XRD and SEM was carried out. The experiments are encouraging. If the oil suited for these characteristics the value addition has been made from this oil which leads to waste land utilization and rural development.