Controlled islanding of power systems considering voltage stability constraints

Abstract

An Intentional Controlled Islanding (ICI) algorithm that directly determines an islanding solution with minimal power-flow disruption for any given number of islands, while ensuring that each island contains only coherent generators was previously proposed and tested using IEEE test systems. The proposed algorithm is based on an exact Mixed Integer Linear Programming Formulation (MILP). However, since voltage instability has been found to be one of the main causes of several recent blackouts in the world, in this paper, the aforementioned algorithm is extended to consider voltage stability constraints. The extended ICI algorithm guarantees sufficient generation capacity (active and reactive power) to match the load consumption within each island. At the same time, it reduces the possibility of voltage collapse by assigning the weakest buses to the islands in such a way to be as close as possible to the sources or sinks of reactive power. The new constraints are expected to further improve the transient stability of the formed islands.