Improvement of Dielectric Strength on Transfomer Wining using New Aramid Paper

Abstract

Large power transformers using perfluorocarbon liquid have advantages of high dielctric strength, excellent cooling ability, and nonflammability.
To make the transformer more compact, it is very important to improve insulation material.
Recently, we succeeded to develop the new type of aramid insulation paper which has no fluff on its surface to avoid field concentration.
In this paper, outline of the developed paper and the experimental results of insulation strength on turn-to-turn and inter-coil models are described.
It was found that the developed new aramid paper makes insulation strength increase 1.2(turn-to-turn case) to 1.7 (inter-coil case) times of the existing insulating paper.