Fault limitation characteristics of a lab-scale resistive type superconducting fault current limiter

With the recent development of advanced YBCO based 2^nd generation (2G) coated conductors (CCs), many researchers started developing superconducting fault current limiters (SFCLs) based on these conductors. We have used an electrically insulated CC developed by Super Power to make a simplified laboratory scale resistive (i.e. non-inductive) type superconducting coil for SFCL technology in Indian power sector. This CC has unique thermal and electrical properties when compared to other commercially available HTS conductors. This YBCO based HTS tape has a silver over-layer and is made on Hastelloy^®276 substrate which is highly resistive by nature. The conductor has polymide (kapton, 30% overlap) insulation for high voltage safety. Using this conductor, we made a small superconducting coil where adjacent turns carry equal and opposite currents to make it non-inductive. This SFCL coil is rated for 220 V_rms and 400 A_rms (single phase) operation. The former of the coil is fabricated in-house using G-10 Glass fiber and fine holes are made on the former for both-side cooling of the CC. In this paper, a simplified design of a resistive SFCL without bypass path is carried out using 2G CCs. After that, the continuous current performance of the coil and voltage drop are measured when 425 A_rms is applied. Over-current test on the coil is carried out to measure the effective fault limitation to verify the performance of the resistive SFCL without a bypass path. (author)