tc-flsfcl provision for improvement of distribution system reliability by topsis based nsga-ii method

an approach for assignment of the optimal location and tap changer adjustment related to flux-lock type superconducting fault current limiters with tap changer (tc-flsfcl) is used in this paper by debating the reduction of fault current flowing from each device and enhancement of reliability varying with customer type in a distribution network connected with distribution generation (dg). tc-flsfcl is a flexible sfcl that it has some preference than previous sfcls. in this type of sfcl the current limiting characteristics are improved and the fault current limiting level during a fault period can be adjusted by controlling the current in third winding, which also made the magnetic field apply to the high-tc superconducting (htsc) element. three objective functions based on reliability index, reduction of fault current and number of installed tc-flsfcl is systematized and non-dominated sorting genetic algorithm-ii (nsga-ii) style is then formed in searching for best location and tuning of tap changer of tc-flsfcl to meet the fitness requirements. a decision-making procedure based on technique for order preference by similarity to ideal solution (topsis) is used for finding best compromise solution from the set of pareto-solutions obtained through nsga-ii. in a distribution network as bus 4 of roy billinton test system (rbts), comparative analysis of the results obtained from application of the resistive sfcl (rsfcl) and tc-flsfcl is presented. the results show that optimal placement of tc-flsfcl than rsfcl can improve reliability index and fault current reduction index with less number