Progress in Superconductivity and Cryogenics (한국초전도ㆍ저온공학회논문지)

The Korean Society of Superconductivity and Cryogenics (한국초전도저온학회)
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Breakdown Characteristics and Survival Probability of Turn-to- Turn Models for a HTS Transformer

  • Cheon H.G. (Department of Electrical Engineering, Gyeongsang National University and Automation and Computer Research Centre of Engineering Research Institute) ;
  • Baek S.M. (Fire Protection Engineering, Changwon College) ;
  • Seong K.C. (Korea Electrotechnology Research Institute) ;
  • Kim H.J. (Korea Electrotechnology Research Institute) ;
  • Kim S.H. (Department of Electrical Engineering, Gyeongsang National University and Automation and Computer Research Centre of Engineering Research Institute)
  • Published : 2005.05.01
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Abstract

Breakdown characteristics and survival probability of turn-to-turn models were investigated under ac and impulse voltage at 77K. For experiments, two test electrode models were fabricated: One is point contact model and the other is surface contact model. Both are made of copper wrapped by O.025mm thick polyimide film(Kapton). The experimental results were analyzed statistically using Weibull distribution in order to examine the wrapping number effects on voltage-time characteristics under ac voltage as well as under impulse voltage in LN$_{2}$. Also survival analysis were performed according to the Kaplan-Meier method. The breakdown voltages of surface contact model are lower than that of point contact model, because the contact area of surface contact model is wider than that of point contact model. Besides, the shape parameter of point contact model is a little bit larger than that of surface contact model. The time to breakdown t$_{50}$ is decreased as the applied voltage is increased, and the lifetime indices slightly are increased as the number of layers is increased. According to the increasing applied voltage and decreasing wrapping number, the survival probability is increased.

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