Analysis of Electric-Field-Dependent Polarization of Triglyceride Ester Oil Molecules Using DFTB-MD Simulations

Natural ester oils, poised to replace mineral oils in DC high-voltage transformers, offer biodegradability and a reduced CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> footprint due to their plant-based origins. However, their polar carboxyl groups, despite aiding environmental benefits, interact with external DC fields, affecting their dielectric properties differently from non-polar mineral oils. Understanding this interaction is vital for assessing insulation effectiveness when combined with polar solid insulators like paper or pressboard. We utilize Density Functional based Tight Binding (DFTB) combined with Molecular Dynamics (MD) simulations to study a model triglyceride ester oil with oleic and linoleic acid chains. Simulations under electric fields from 0 to 100 kV/mm reveal the electric field's influence on the structural dynamics and dipole moments, crucial for understanding ester oil polarization and insulation properties.