Behavior of alternative electro insulating liquid at solidification process

The most commonly used insulating liquid is mineral oil. Mineral oil is characterized by high flammability and poor biodegradability. On the other hand, this oil has very good electrical properties. For reasons of environmental protection is an effort to replace the mineral oil by alternative insulating liquids. The vegetable or synthetic oils may be used as an alternative insulating liquid. The rapeseed oil is a suitable replacement for mineral oil in terms of dielectric properties, environmental friendliness, and financial costs. The main objective of this paper is to analyze the influence of solidification of rapeseed oil on its dielectrics parameters by dielectric spectroscopy measurement. The main emphasis is placed on the area near the pour point. The comparison of the dielectric strength of rapeseed oil in the liquid state and in the solid state is also part of this research.