Comparative study to understand behaviour of natural ester as transformer insulating liquid

Abstract

There is a growing interest to use natural esters as insulating liquids in power transformers, yet current experience in use of these liquids is inadequate for cost effective and reliable field applications. To reduce this gap a study has been done to measure the properties of a commercially available natural ester based insulating liquid and compared its ageing performances with conventional mineral oil based insulation. Moreover, ageing behavior of cellulosic pressboard insulation in the natural ester is also compared to that of in mineral oil. This study simulate the FDS response of both mineral and natural ester filled transformer under different conditions including, oil replacement, drying out of solid insulation and replacement of aged mineral oil with new natural ester based insulating liquids.