Analysis and comparison of actual behavior of oil-type and dry-type transformers during lightning

Abstract

This study aims at analyzing behavior and state of oil-type and dry-type transformers during lightning strikes. Since lightning is an inevitable phenomenon in electricity grids, this issue should be considered in design stage of grid and transformer and also implementation of transformer in the electricity grid. As different protectors exist in generation and transmission transformers, distribution transformers have been taken into account in this study. The impact of lightning strike on the distribution transformers is usually diminished with the help of earth system or protectors. However, the effect of lightning on transformer insulation is not negligible. Thus, it should be investigated. Behavior results have been given in a comparative manner in order to present a better understanding of transformers' insulation behavior.