Space charge behaviour on epoxy based dielectrics filled with micro and nano silica

Epoxy based compounds containing micrometric and nanometric silica were prepared. These were utilized in a comparative study to establish their dielectric behaviour. In this study, the weight %-content of the silica filler was varied as a parameter. Some filler distributions were characterized using TEM. In general, the micrographs illustrate a satisfactory dispersion, showing a nanostructured morphology. The polarizability of the various materials is established and compared using dielectric spectroscopy. Indeed, the polar nature of the dielectric can affect the space charge accumulation. Space charge was studied using the Thermal Step Methop (TSM). We observed the ability of the different materials to accumulate space charges after an electrical and thermal poling close to practical applications. The influence of the combination of micro and nano filler is highlighted. A classification of the studied materials regarding their space charge accumulation is done.