计及放电形态和发光特性的变压器油中流注传播模式分类OA北大核心

Under the action of strong electric field,the streamers in transformer oil can get step development at a spe-cific threshold voltage and induce insulation failure in the large oil gap in the actual operation of transformer.Howev-er,the presently used common'4 modes'classification method can only reflect the variation extent of average devel-opment speed in case of abrupt variation of the streamer discharge,but cannot effectively distinguish the abrupt varia-tion pattern and mechanism of streamers in transformer oil with different physical and chemical characteristics.In this paper,the gas paraffin oil and natural ester commonly used in transformers is used as the study object,the streamer discharge pattern and the accompanying photoelectric signal in a 25 mm point-plane electrode structure are measured under the standard lightning impulse voltage.Based on the consideration of traditional parameter of the av-erage development speed of the streamer discharge,such two types of characteristic components as the fractal dimen-sion of discharge and amplitude of photoelectric signal are introduced to perform a three-dimensional clustering anal-ysis of the streamer discharge development.The study results show that the improved classification of the streamer propagation mode,compared with the'4 types of mode'classification method,has more obvious effect on the differ-entiation of the 1st and 2nd mode slow streamers and the 3rd and 4th mode fast streamers.Furthermore,the under-standing of the variation of the streamer discharge pattern in case of voltage variation and the influence mechanism of the variation trigger as well as the streamer pattern jump phenomenon are strengthened.