KIEE International Transactions on Electrophysics and Applications

대한전기학회 (The Korean Institute of Electrical Engineers)
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Effects of Temperature and Pressure on the Breakdown Characteristics of Liquid Nitrogen

  • Baek, Seung-Myeong (Dept. of Electrical Engineering, Gyeongsang National University and Engineering Research Institute) ;
  • Joung, Jong-Man (Dept. of Electrical Engineering, Gyeongsang National University and Engineering Research Institute) ;
  • Kim, Sang-Hyun (Dept. of Electrical Engineering, Gyeongsang National University and Engineering Research Institute)
  • 발행 : 2003.10.01
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초록

For practical electrical insulation design of high temperature superconducting (HTS) power apparatuses, knowledge of the dielectric behavior of both liquid nitrogen (L$N_2$) and subcooled liquid nitrogen (SL$N_2$) are essential. To achieve SL$N_2$ at atmospheric pressure, cryostat was designed and constructed. By pumping up the L$N_2$ in the outer dewar, the temperature of L$N_2$ in the inner dewar at atmospheric pressure can be controlled. The breakdown characteristics of L$N_2$ in quasi-uniform and non-uniform electrical fields for temperatures ranging from 77 K to 65 K at atmospheric pressure and pressure ranging from 0.1 to 0.5 MPa were investigated experimentally. The experimental data suggested that the breakdown voltage (BDV) of L$N_2$ is both highly temperature and pressure dependent. We also carried out statistical analysis of the experimental results using the Weibull distribution. The Weibull shape parameter m for the sphere-to-plane electrodes in SL$N_2$ was estimated to be 11 to 18.

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참고문헌

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