Research on Morphological Characteristics of Partial Discharge in Oil-paper Insulation Based on Image

Oil-paper insulation structure is the main part of the insulation system of oil immersed power transformer, which is prone to partial discharge due to aging, moisture and other factors. In order to study the development process and evolution characteristics of discharge, and explore its influencing factors and mechanism, this paper built an oil-paper insulation discharge test observation platform, obtained discharge images through the high-speed camera, and analyzed the area, perimeter, and displacement changes of streamers during the development of discharge. The results show that the overall trend of streamer area and perimeter is to increase first and then decrease, and rise with the increase of needle plate gap within a certain range. During the discharge process, the streamer basically develops along the axial direction from the needle tip to the paperboard, extending randomly to the left and right sides, with the largest mid-term offset. The thickening of the paperboard will increase the lateral tilt probability of the streamer. The above research results can provide theoretical guidance for the design, manufacture, maintenance and operation of transformers.