Multi-criteria contingency ranking method for voltage stability

The objective of this paper is to propose a fast, accurate, and robust method for ranking contingencies according to their severities as far as voltage stability is concerned. In general terms, the proposed procedure consists of obtaining the operating state and computing performance indices for each contingency of a predefined list. The contingencies are then ranked according to their performance indices. The proposed method can be used as a real time operation tool, since its computational effort is very small. The proposed method is able to pick most of the severe contingencies, resulting in very good capture ratios. Simulation results are shown for small test and large realistic power systems.