Two-layered EPSO for maximizing loadability with FACTS devices

This paper proposes an efficient method for maximizing power system loadability with the optimal allocation of FACTS (Flexible AC Transmission System) devices. In recent years, renewable energy such as PV systems and wind power generation is positively introduced into power systems to reduce the emission of CO2. However, such generation units are inclined to provide variable output due to the change of weather conditions. In this paper, a hybrid meta-heuristic method is proposed to determine the optimal allocation and the optimal variable output of FACTS devices under variable generations to maximize loadability at the specified nodes. The proposed method is based on two-layered Evolutionary Particle Swarm Optimization (TLEPSO) to solve the nonlinear mixed integer problem of the optimal allocation of FACTS devices. To consider the uncertainty of PV systems, the Monte-Carlo simulation is carried out to evaluate the probabilistic characteristics of loadability at the specified node in probabilistic power system conditions. The proposed method is successfully applied to a sample system.