Evaluation of the electrical properties of epoxy-based nanocomposites for motor insulation

Polymeric nanocomposites are increasingly adopted for replacing conventional insulation to provide enhanced performances such us reliability, environmental compatibility and power rating in new generation inverter-fed Adjustable Speed Drives electrical motors. This paper describes an experimental study aimed at evaluating the performances of several candidate nanocomposites obtained by adding different clays to an epoxy matrix already used for manufacturing motor insulation system. The electrical, thermal and mechanical properties of the nanocomposites are investigated in order to evaluate their performances as new impregnation materials in multilayered insulation systems. The effect of the different clays on the dc conductivity and permittivity is investigated as a function of the electric field and temperature applied to the nanocomposites.