earticle

영어

A sub-cooled liquid nitrogen system is known as a promising method to develop high voltage superconducting apparatuses such as superconducting fault current limiters (SFCLs) and superconducting cables. To develop a high voltage superconducting machine adopting the sub-cooled liquid nitrogen system with a constant pressure, injecting a non-condensable gas is indispensable. In this study, the dielectric characteristics of insulation gases are investigated and analyzed by using electric utilization factors (ξ). It is found that the maximum electric field at sparkover that occurs with 50 % probability, EMAX,50% exponentially decreases as the ξ increases. This means that the EMAX,50% at sparkover can be estimated with the ξ only, without any other electrical insulation test. This result is applicable to developing the gas insulated high voltage superconducting electric power apparatuses.