Optimal Placement and Sizing of Fault Current Limiters: A Voltage- Stability-Constrained Approach Considering Transmission Switching

As power system network structures expand and integrate advanced system devices, the ever-increasing short-circuit current (SCC) hinders further development. Fault current limiters (FCLs) and transmission switching (TS) are widely- recognized measures to counteract SCC. However, TS can adversely impact system voltage stability, a factor commonly overlooked in SCC research. Additionally, a combined framework that incorporates both FCL investment and TS remains elusive. This paper proposes a novel voltage-stability-constrained planning framework to ascertain the optimal placement and sizing of FCLs while also considering economy and SCC limiting effects of TS. Formulations for both FCL investment and transmission switching effects on SCC magnitude are presented. Based on these formulations, the proposed planning model is cast as a mixed-integer linear programming (MILP) problem. To ensure a voltage-stable and economically feasible solution, the model integrates voltage stability requirements to prevent potential voltage collapse after switching lines. The effectiveness of the proposed model is evaluated using the IEEE 30-bus and 118-bus systems, demonstrating both its economic benefits and voltage stability guarantees.