Optimal allocation of superconducting fault current limiters considering voltage sags mitigation

This paper presents a new problem formulation for allocation of superconducting fault current limiter (SFCL) for reducing fault current and mitigation of voltage sag. The analytic expressions for calculation of voltage sag with SFCL are derived. A new optimal model is established for allocating the installation location, impedance values and critical quench current of SFCL. The optimal objective function includes the area of vulnerability and voltage sag amplitude. The constraints include the target of reducing fault current and investment planning of SFCL. Using chaotic particle swarm optimization (PSO) and the improved discrete particle swarm optimization (DPSO) algorithm solve the optimal problem. The enumeration method is used to determine to install SFCL in the beginning or the end of lines. Finally, the proposed method is validated in the IEEE39-bus test system.