Application of resistive super conductor fault current limiter for protection of grid-connected DGs

Abstract

Penetration of Distributed Generation (DG) into the power system causes technical problems and bad effects on the safety of the system due to increasing the short circuit levels in transmission and distribution networks. So, there will be miscoordination problems of directional over current relays (DOCR) when DGs are integrated with looped power delivery systems. This paper presents a new approach of implementing resistive superconducting fault current limiters (SFCL) with DG units to obtain optimal setting of protection system. The protection coordination setting is optimized using particle swarm optimization (PSO) technique. The proposed algorithm is tested on nine-bus looped power distribution system and the effects of SFCL on protection system of DG-grid connected are analyze. Three cases are studied: no DG, grid-connected DGs with SFCL and grid-connected DGs without SFCL. Several simulations are implemented for different locations of fault. Keywords: Particle swarm optimization, Directional over current relays, Superconducting fault current limiters, Distributed generation