Dynamic security assessment to improve system stability

This paper presents a dynamic security assessment solution, which can be used in the system control room to improve system stability. It is based on a set of security indices. The indices are able of establishing contingencies´ severity levels as a measure of different aspects of power system security. A system based on fuzzy logic is used to combine the indices into a single composite index. The composite index is able to alert the control operator to conditions that represent a significant risk to system security based on over-all system performance.