Quench Characteristics of High Temperature Superconducting Coil for Fault Current Limiting Application

Hyundai Heavy Industries Co., Ltd. (HHI) has developed a prototype of high temperature superconducting (HTS) fault current limiter (FCL) in Dec. 2006. The ratings of the HTS FCL were 13.2 kV in voltage and 630 A in current at normal condition. This HTS FCL had a HTS coil composed of 7 concentric HTS windings for current limiting element which are wound by using unique bifilar method with YBCO coated conductor (CC). The CC wound on the bobbin was insulated with Kapton tape and the HTS coil was completed assembling the windings using copper connection parts. The HTS coil was cooled down to 65 K for the enhancement of cryo-dielectric performance and critical current capacity. The short-circuit test was performed with the asymmetrical prospective fault current of 10 kA. The resistance of HTS coil began to rise up from 0.624 ms after the fault. At about 1/4 cycle after the fault, the temperature of HTS coil exceeded its critical temperature. The resistance and temperature of HTS coil after 0.1 s from the fault was calculated to be about 11.8 Omega and 250 K respectively which was designed to be about 13 Omega and 300 K.

I. Introduction

The HTS FCL is considered as the best device for fault current limitation and many researches are being performed for high voltage application and commercialization at distribution power system.