Propagation of creepage discharge on the surface of solid insulator in transformer oil

摘要

There is a comparatively regular pattern composed of peaks-troughs on the surface of a pressboard (PB), the pattern of which is formed in production process and is different by a maker. In the present paper, we use a point-plane electrode as an electrode system, the PB is placed between these electrodes, and turning our attention to the pattern of the PB surface, the creepage discharge in transformer oil on three kinds of the pressboards, which have the different pattern, is observed in detail. As a result, the influence of the surface state of the PB on the creepage discharge is investigated by a high speed schlieren method, a video camera observation system and a current measurement system by LED.