Thermodynamic study of compound Mica — Epoxy Resin based on dissipation factor tests — Internal energy

In this paper an electrical equivalent of the internal energy based on dissipation factor tests of compound Mica - Epoxy Resin used as insulating material in the stator bars of electrical machines is shown. To this, 15 samples were designed and subjected to Step Voltage Endurance Test (SVET) at a constant temperature of 90°C. Before and during each period of aging, the dielectric losses by means of dissipation factor test of each sample were measured at a voltage of 2 kV, where it assumes the non-presence of partial discharges within the material, and within a temperature range. The results of the dielectric losses were used to determine the caloric coefficients and glass transition temperature of the material for the different stages of aging of the insulation.