Comprehensive coordination of radial distribution network protection in the presence of synchronous distributed generation using fault current limiter

Synchronous Machine-based Distributed Generations (SMDGs) are integrated into distribution networks due to their benefits. However, they may cause problems for protection systems, especially in radial distribution networks. In this paper, a coordination algorithm is proposed to modify Time Multiplier Setting (TMS) and pickup current settings of the protective devices, e.g. overcurrent relays, reclosers and fuses, in order to overcome conventional problems of installing SMDGs, e.g. nuisance tripping and fuses blowing, caused by the reverse fault currents of the SMDGs. The proposed algorithm employs the Fault Current Limiter (FCL), as well as re-coordination algorithm, to restore coordination of protection systems in radial distribution networks with high penetration of SMDGs. For this purpose, a multi-objective optimization algorithm is used to determine the minimum size of FCL and optimal setting of protection system. The algorithm is formulated based on hybrid genetic algorithm (GA) and linear programing (LP) method to reduce computation time. Simulations are carried out on a realistic distribution network, and the results demonstrate that the proposed method provides feasible and effective solutions for optimal coordination restoration, while minimizing the FCL size.