Contingency Selection of Branch Outages Causing Voltage Problems

The purpose of steady-state power system security analysis is to determine which contingencies cause component limit violations and also the severity of any such violations. For large systems, even if only single component contingencies were considered, and even if fast solution methods were employed, full AC analysis of all cases could be prohibitively time consuming. Contingency selection involves estimating in advance which contingencies are likely to cause limit violations followed by AC analysis of only these cases.