Pre-screening of single contingencies causing network topology changes

A multilevel contingency screening method is introduced to process large sets of candidate power system contingencies. The idea is to apply a series of increasingly more accurate and time-consuming algorithms so that each higher screening level processes a reduced set of candidates. A practical implementation of the method uses a fast prescreening step whose algorithm is based upon the local network solution concept. The method is designed to process contingencies whose effects can be localized, e.g. branch outages and bus section faults. The accuracy of the new algorithm is controlled via an automatically calculated small network adequacy ratio while its reliability is enhanced by the use of different contingency severity measures