Assessing the dielectric performance of Sclerocarya birrea (Marula oil) and mineral oil for eco-friendly power transformer applications

Abstract The ever increasing power demand has forced the power sector companies to increase their generation, transmission and distribution in turn increasing the number of power transformers in the system where necessary. Depending on the nature of operations, the transformers are chosen as either dry-type or liquid-cooled and the preference is mostly liquid cooled. Naphthenic oils have been the primary choice over the years and alternative solutions in the form of natural esters are researched extensively due to the environmental effects of Mineral Oil (MO). One such ester, Marula is presented in this research. The experiment places its focus on measurement of electrical, physical, chemical and thermal characteristics as per the standards of ASTM and IEC. The results prove the superior dielectric performance of MAO over MO. The antioxidant rich MAO exhibits superior dielectric properties and restores faster than MO after the instances of breakdown phenomena. The antioxidants show stability at both the low and high temperatures, and temperature causes minimum damage to antioxidants. In addition to that the use of such dielectric coolant minimizes the winding damage inside the transformer tank. Thus, it can be said that MAO is an excellent coolant and improves the efficiency of the transformer without the requirements of additional cooling devices.