A novel sensitivity analysis for optimal design of superconductive fault current limiter in microgrids

Several studies concluded that installing superconductive fault current limiters (SFCLs) at generators’ sides in microgrid systems (MGSs), at the secondary side of each transformer in the system, at each load or at the location with most fault occurrences improve both the reliability and the stability of the system. However, increasing the number of SFCLs in the system leads to an increase in the cost. This paper intents to find the optimal locations and size of SFCLs to improve the stability and the reliability of the studied MGS during a faulty condition by protecting transformers in the system from tripping. The number of SFCLs should be less than the number of transformers which leads to less cost of the initial installations. In order to achieve this goal, this paper presents a novel sensitivity analysis inside a multi-objective optimization method to find the best solution for the optimal location and size of the SFCLs. A line outage distribution factor sensitivity analysis method is utilized to investigate the effect of line outage on the entire system. Also, the effects of each location in the system have been taken into consideration in this study. The results in this paper prove the robustness of the proposed approach which enhances the stability and reliability of the power network while minimizing the required impedance and number of SFCLs.