Title |
AC Insulation Breakdown Properties of the EMNC to Application of Distribution Molded Transformer |
DOI |
https://doi.org/10.5370/KIEE.2013.62.5.649 |
Keywords |
Electric fields dispersion ; Epoxy microcomposites(EMC). Epoxy microsilica-nano layered silicate composites(EMNC) ; AC insulation breakdown strength ; Glass transition temperature ; DMA |
Abstract |
A conventional epoxy-microsilica composite (EMC) and an epoxy-microsilica-nanosilicate composite (EMNC) were prepared in order to apply them to mold-type transformers, current transformers (CT) and potential transformers (PT). Nanosilicate was exfoliated in a epoxy resin using our electric field dispersion process and AC insulation breakdown strength at 30~150°C, glass transition temperature and viscoelasticity were studied. AC insulation breakdown strength of EMNC was higher than that of EMC and that value of EMNC was far higher at high temperature. Glass transition temperature and viscoelasticity property of EMNC was higher than those of EMC at high temperature. These results was due to the even dispersion of nanosilicates among the nanosilicas, which could be observed using transmission electron microscopy (TEM). That is, the nanosilicates interrupt the electron transfer and restrict the mobility of the epoxy chains. |