Voltage contingency selection technique for security assessment

The authors present a fast and accurate technique for ranking transmission line outages according to the severity of their effects on busbar voltages. To simulate each contingency case, the proposed technique uses the DC formulation with compensation method to compute the post outage angle and the superdecoupled load flow formulation, and compensation method to derive the post outage voltage. The quadratic voltage performance index for every line contingency is then computed, and the results are subsequently sorted in descending order, according to the severity of effects. Computational results of this technique, applied to different test systems, are presented.<>