Study of dielectric properties of mineral oils and natural oils and methyl esters of natural oils

This paper deals with the analysis of perspective and environmentally-friendly electrical insulating liquids for electrical engineering. Dielectric properties were measured using the high-resolution Novocontrol Alpha-A Frequency Analyzer in the frequency range 1 Hz-1 MHz in the temperature interval 243 K-363 K. The lowest value of dielectric constant of non-inhibited mineral oil (2.22) was exhibited at 363 K by Mogul Trafo N. Methyl oleate, an oil component which is usually present in large quantities, exhibited the value of dielectric constant equal to 3.23. MCT oil (oil contains triglycerides of medium chain) exhibited the value of dielectric constant equal to 3.93.