원문정보
초록
영어
A liquid nitrogen (LN2) is usually used to be a coolant and insulant for a HTS coil system. HTS wires for a superconducting apparatus may be surrounded by gaseous nitrogen (GN2) due to film boiling generated by a quench or voids occurred by electrical breakdown. The increased maximum electric field intensity at GN2 may result in the degradation of dielectric strength of a HTS coil system. In this paper, a study on the dielectric characteristics of a composite insulation system composed of LN2 and GN2 is performed. A sphere-to-plane electrode system made with stainless steel is used to perform the experiments under AC and lightning impulse voltage condition. A sphere electrode is surrounded by GN2 and a plane electrode is immersed into LN2 to conduct dielectric experiments with a composite insulation system. The dielectric experiments are performed according to the level of LN2 from the plane electrode to a sphere electrode. It is found that the dielectric characteristics of a composite insulation system are dependent on the level of LN2 and the field utilization factor of an electrode system.
목차
1. INTRODUCTION
2. EXPERIMENT
2.1. Experimental Set-up
2.2. Experimental Results
2.3. Electric Field Analysis
3. DISCUSSION
4. CONCLUSIONS
ACKNOWLEDGMENT
REFERENCES