A novel method of look-ahead contingency ranking for saddle-node bifurcation

The objective of this paper is to present a powerful procedure for identifying severe single branch outage contingencies with respect to saddle-node bifurcation, given a power system operating point, a load demand forecast and a generation dispatch. A novel two-stage look-ahead ranking algorithm for saddle-node bifurcation are described. The first stage is based on a branch MVAr participation index and the second stage is based on sensitivity analysis. The distinguishing features are the ability: (i) to screen out the weak contingencies; and (ii) to directly estimate the strong contingency bifurcation values. The novel two-stage look-ahead ranking algorithm has been applied to a 3493 bus power system with promising results.