Security analysis for voltage problems using a reduced model

The authors present a new algorithm for power system security analysis considering voltage security problems. The approach is based on the newly developed adaptive prefilter (APF). Reduced models are used for both contingency selection and analysis. A fast and reliable prescreening procedure is used to screen out a large portion of noncritical cases at very little cost and provide the information needed in building reduced models for the selection and analysis procedure after the prescreening. Tests show that the proposed approach is fast and reliable. The efficiency of this algorithm is achieved due to the following; a large portion of noncritical cases are filtered out at very little cost by the APF module, fast one P and fast one Q iterations are used for the contingency selection, and reduced models are used for the AC analysis, and some of the 1P-1Q iterations applied in the contingency selection are utilized in the contingency analysis procedure. >