A comprehensive approach for FACTS devices optimal allocation to mitigate voltage collapse

This paper presents a comprehensive approach for optimal allocation of FACTS devices against voltage collapse. The objective is to install a minimum number and sizes of FACTS so that the preventive and corrective control are made possible based on the available VAR sources and new FACTS devices for a set of contingencies. The corrective control is to stabilize the system for the contingencies that drive the system to unstable zone, where the fast devices are merely used for these situations. The preventive control is assumed based on the slow and fast devices for the cases with an inadequate security margin. The problem is formulated as mixed integer nonlinear programming problem, where a hybrid method based on genetic algorithm/successive linear programming (GA/SLP) is used to find the optimal solution.