Superconducting Fault Current Limiters for Multi-terminal DC Grid Applications

During the last decade there has been an increasing interest in the High Voltage DC grids amongst researchers and policy makers. Protection has been identified as a critical component in the realization of these multi-terminal direct current (MTDC) systems. The fault currents in the DC systems are limited by the circuit resistance and inductance and thus are likely to reach very high values. This may also lead to voltage collapse. In order to limit the fault current magnitudes and to prevent voltage collapse use of superconducting fault current limiters (SCFCL) in MTDC system is proposed in this paper. The effectiveness of SCFCL in limiting the fault current along with sizing of SCFCL resistor are explored in this paper. The paper also discusses the effect of initial discharge and critical current setting of SCFCL.