NSGA-II Based Multi Objective Design Optimization of Resistive Superconducting Fault Current Limiters

Superconducting fault current limiters (SFCLs) are the devices that uses the superconducting properties of the materials to limit the fault current. In comparison to the conventional fault current limiters (FCLs), the SFCL has advantage that its current limiting property is inherent and no external controls are required. However, to achieve the exact current limiting ratings with other characteristics like quench time, recovery time, peak current etc. a design optimization is required. Since the whole characteristics of SFCL depends upon the superconducting material adopted, and the parameters of cooling systems. The parameters defining the behavior of these two entities are selected as optimization variables. Because in this work second-generation high temperature superconducting (HTS) material known as YBCO (Yttrium Barium Copper Oxide ) is considered. Hence, in this paper non-dominated Sorting GA (NSGA-II) optimization algorithm is adopted that exploits the 2G YBCO mathematical model relating its electrical and thermal characteristics and cooling system specifications to find the optimal parameters according to the requirements (or objectives) of resistive-SFCL. The simulation results show that the presented algorithm is able to achieve multiple design objectives (required for SFCL) simultaneously within the range of 5%.