Probabilistic evaluation of voltage stability

This paper presents a contingency enumeration based approach to evaluate the voltage stability of a power system. The proposed approach, includes the selection and evaluation of contingencies, the classification of contingencies according to selected failure criteria and the accumulation of voltage stability indices. Voltage stability is quantified in the form of indices such as the probability and frequency of voltage instability and the expected voltage stability margin. Investigations using this approach have been conducted on a small test system and on the IEEE Reliability Test System.