Study on Insulation Prediction of Triple Junction in $SF_6$

$SF_6$ 가스 중의 삼중점 절연파괴 예측기술에 관한 연구

  • 조용성 (한국전기연구원 전력기기연구센터) ;
  • 정진교 (한국전기연구원 전력기기연구센터) ;
  • 이우영 (한국전기연구원 전력기기연구센터)
  • Published : 2009.05.01

Abstract

Triple junction which consists of three media(electrode, insulator, and gas) should be considered in designing of high voltage equipments due to the electric field enhancement. In this paper, positive lightning impulse breakdown voltage is predicted based on the streamer theory for simplified insulator models and 72.5kV spacer with varying the triple junction geometry and gas pressure, and the results are compared to the experimental results. The electric field coefficient concept is also applied in order to evaluate the partial discharge inception voltage and the surface flashover voltage from the streamer inception voltage. The application of this method using the constant electric field coefficient of 1.3 and 0.66 is possible for evaluating the triple-junction insulation of the simplified insulator and the 72.5kV spacer respectively. The error rate is under 10%.

Keywords

Triple junction;Streamer;Surface flashover;Lightning impulse;Insulator

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