Multi-terminal DC Fault Current Estimation Including the Influence of Superconducting Fault Current Limiters

Hybrid DC Circuit breaker (DCCB) are the key enabling technology in the development of Multi-terminal DC (MTDC) grids. However, recent DCCB solutions suffer from limited fault clearing capability due to limited maximum switch-off current and interruption time. To reduce the DC fault currents to manageable values, additional hardware, such as resistive Superconducting Fault Current Limiters (SCFCL), needs to be added to the system. This article analyzes the influence of resistive SCFCL in MTDC grids by means of analytical fault current estimation including the equivalent exponential model of SCFCL. A parameter variation analysis is performed to show the impact of SCFCL on fault clearing capability of hybrid DCCB.