A Continuation Method Approach to Finding the Closest Saddle Node Bifurcation Point

The paper considers the problem of nding saddle node bifur-cation points which are closest (in a local sense) to the power system operating point. This optimization problem leads to a set of equations which describe such critical points. Not all solutions of this set of equations are critical points. The paper therefore explores the nature and characteristics of solutions. A two stage algorithm is proposed for solving the critical point problem. The rst stage is simply to nd a point on the singular surface, i.e., the surface of saddle node bifurcation points, which lies is a speciied direction. The second stage uses a continuation method to move from that initial point to the desired critical point. Singularity of the critical point problem can have a signiicant innuence on the robustness of the continuation method. The paper investigates singularity conditions. The proposed algorithm is tested on an eight bus power system example.