AC breakdown characteristics of ultra violet curable epoxy resin with nitrogen fine bubbles

Abstract

We investigated AC breakdown characteristics of ultra violet curable epoxy resin (UV‐EP) with nitrogen fine bubbles (FBs) in order to improve insulating properties of UV‐EP. As a result, it was found that self‐made FB generator mainly add FBs with a diameter between 60 and 150 nm to FB‐EP before curing. In addition, SEM images revealed that FB‐EP has FBs after curing. Bubble diameter in FB‐EP after curing was estimated between 55 and 140 nm due to resin shrinkage. Furthermore, partial discharge inception voltage and electric strength of FB‐EP with FB addition for 10 min were almost the same as No FB‐EP.