불균등 전류 분배 조건에서 병렬 권선된 고온 초전도 코일의 교류손실 특성에 관한 분석

Analysis on AC Loss Characteristics of Parallel Wounded High Temperature Superconducting Coil under Unequal Current Distribution Conditions

Usually, electric machines are operated on 60Hz frequency. Therefore, AC loss problem has been economically an important factor for the application of electric machines using HTS(High Temperature Superconductor). The AC loss generated in HTS is related to cooling system of electric machines. Additionally unlike non-inductive electric machines, the AC loss of inductive electric machines such as transformers and a fault current limiter is much bigger. These reasons are why the AC loss in HTS is supposed to be researched for stable operation of electric machines. This paper deals with the AC loss characteristic of parallel wounded HTS coils under unequal current distribution conditions. To measure the AC loss dependency on various current distributions, inductive solenoid coils using GdBCO HTS tape and BSCCO-2223 tape were fabricated. The experiments were carried out at 77K liquid nitrogen and result data was measured by an electrical method. We set up a variable resistor to adjust current distribution at each coil compulsorily. From the experimental data, when the current unequally distributed, the AC loss of HTS solenoid coils increased whether which tape was used. The proposed result data in this paper would be valuable to develop electric machines using HTS coil.