Liquid dielectrics

The present Special Issue is devoted to papers, which deal with the subjects of liquid dielectrics. Most of the papers included in the present Special Issue are concerned with innovative insulating liquids belonging to the family of natural and synthetic esters. The large interest in ester liquids is due to their positive property to have a much higher flash points and fire points of over 300 °C, almost two times more than traditional mineral oils; in addition, natural esters are readily biodegradable and come from renewable resources, made out of seed crops, such as soybeans. In fact, scientific researches on advances related to these liquids are needed for the development of safer power transformers as essential part of the forthcoming announced green-economy, now no longer postponed for the benefit of our planet. The main validation points for these innovative liquids remain their dielectric behavior and their aging performance and for this reason outstanding researches are still going on. Other papers included in this Special Issue deal with important studies related to breakdown, partial discharge (PD) and the effort made worldwide to improve the liquid insulation properties through the use of innovative nanomaterial additives.