Assesment of over-current protection for superconducting cables

The objectives of the studies presented in this paper aim to assess the sensitivity and the stability margins of conventional overcurrent protection schemes for the protection of Superconducting Cables with High Temperature Superconducting tapes. The ultimate goal is to identify the limitations and particularities of the conventional over-current relays to provide sensitive and reliable protection for the superconducting-based power grids. For this purpose, a verified model of Superconducting Cable developed in Matlab/Simulink and has been utilized to examine its transient performance and obtain profound insights of the quenching phenomenon. The case studies include different types of internal faults applied on the Superconducting Cable and external faults occurring on the adjacent feeders. The results and observations included in the paper, identified that due to the inherent dynamically-changing resistance and the mutable operating stages of the SC, the reliability and the discriminative capability of the conventional over-current relays are compromised.