Progress in Superconductivity and Cryogenics (한국초전도ㆍ저온공학회논문지)

The Korean Society of Superconductivity and Cryogenics (한국초전도저온학회)
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Breakdown Properties of Coolant for HTS Apparatus Operating at Cryogenic Temperature

  • S.M. Baek (Electrical material lab., Department of Electrical Engineering, Gyeongsang National University and Automation and Computer Research Centre of Engineering Research Institute) ;
  • J.M. Joung (Electrical material lab., Department of Electrical Engineering, Gyeongsang National University and Automation and Computer Research Centre of Engineering Research Institute) ;
  • Kim, S.H (Electrical material lab., Department of Electrical Engineering, Gyeongsang National University and Automation and Computer Research Centre of Engineering Research Institute)
  • Published : 2003.05.01
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Abstract

For the dielectric insulation design of any high temperature superconducting (HTS) apparatus in the electrical power systems, the breakdown properties of cryogenic coolants such as $LN_2$ are an important factor of the insulating engineering. Therefore, this paper presented an experimental investigation of breakdown phenomena in $LN_2$ under AC voltage. And we studied the breakdown properties of LN2 with decreasing temperature. Also, the Weibull plots of the breakdown voltage of subcooled $LN_2$ at 65 K for the needle-plane electrode with electrode distance d= 10 mm are studied. The dependence of breakdown voltage for needle-plane and pancake coil-pancake coil electrode on temperature is illustrated. The experimental data suggested that the breakdown voltage of L$N_2$ depend strongly on the temperature of $LN_2$. The breakdown characteristics of $LN_2$ under quasi-uniform and non-uniform electrical field for temperature ranging from 77 K to 65 K were clarified.

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References

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