Application and positioning analysis of a resistive type Superconducting Fault Current Limiter in AC and DC microgrids using Simulink and SimPowerSystem

Abstract

Conventional protection devices installed for the protection of excessive fault current in the electric power system have a certain response time delay resulting in power system to pass initial peaks of fault current. Superconducting Fault Current Limiter (SFCL) is a novel technology which has negligible power loss and capability to quench initial fault currents instantly and it also could be utilized to cope with excessive fault current problems in upcoming microgrids. This paper presents feasibility analysis results of positioning of the SFCL and its effects on reducing fault current in microgrids. The detailed power system having AC and low voltage DC microgrids consist of integrated wind and photovoltaic farms integrated with a traditional power system is modeled. Transient analyses for the microgrids were performed for the worst case faults with SFCL installed at key locations of the microgrids. It has been observed that SFCL should not be installed directly at the substation or the branch network feeders. This placement of SFCL results in abnormal fault current contribution from the DG sources. The strategic location of SFCL in power grid which limits all fault currents and has no negative effect on the DG sources is found to be in front of the point of integration of the DG sources with the microgrid.