Multiphysics Modelling And Thermal Performance Of A Prototype Transformer Filled With Bio-Based Insulating Oil Under Various Load Conditions

Before designing and engineering an environmentally friendly immersion transformer, it is important to consider its thermal performance. Increasingly bio-based insulating oil develops as alternatives to mineral oil for transformers. The characterization of these bio-insulators by the standards for insulation for electrical materials in use is the problem. This paper provides a partial answer to this problem by presenting a numerical study based on the finite element method of the thermal performance of a prototype 3 KVA 50 Hz power transformer filled with bio-insulators for the cases of different loads. Using COMSOL Multiphysics 5.4, a multiphysics model was designed to evaluate the temperature distribution for each insulator (mineral oil (MO), castor oil methyl ester (COME), palm kernel oil methyl ester (PKOME), and palm kernel oil methyl ester plus nanoparticles of titanium (PKOME+NANO)) under various loads. To predict the temperature evolution by estimating the hot spots and to optimize the choice of the type of liquid insulation for power transformers at the scientific level, the thermal property models were integrated into COMSOL using the finite element method. We found that taking into account the temperature evolution of the hot spots in the transformer, the one filled with natural ester can resist aging more than the one filled with mineral oil for different loads. Therefore natural esters can be alternatives to mineral oil for power transformers. However, mineral oil has better thermal inertia than the natural esters in our study