Optimal SVC placement for voltage stability enhancement of power systems under critical operation conditions

This paper presents a messy genetic-algorithm-based optimization scheme for placement of static VAR compensators (SVCs), aimed at voltage stability enhancement of power systems under critical operation conditions. The SVC planning was formulated as a multiobjective optimization problem in terms of maximum worst-case reactive power margin, highest load voltages towards the critical operating points, minimum real power losses and lowest costs of SVC devices. During the genetic algorithm search for the optimal solution, the most critical disturbance scenario was estimated with the configuration of the original power system and each candidate of the SVC placement. The approximation can greatly simplify the SVC planning. By employing a fuzzy performance index, the multiobjective optimization was further transformed into a constrained problem with a single objective function