Electrostatics in Power Transformers

Abstract

In this paper, the streaming electrification in core type forced oil cooled power transformers is investigated, using a full-scale model transformer and various experimental models. It has been clarified that streaming electrification in transformers is influenced mainly by flow rate, oil temperature, surface conditions of insulating materials and characteristics of insulating oil. Electrostatic discharge occurs eventually when the amount of local charge exceeds a certain limit.