DETERMINATION OF CLOSEST SADDLE NODE BIFURCATION POINT FOR POWER SYSTEM USING SINE COSINE AND RAO-1 METAPHOR-LESS ALGORITHMS

The maximum loadability point of a power system is usually termed as saddle node bifurcation point (SNBP). This is also known as voltage collapse point on a PV-curve. The distance to voltage collapse point from the current operating point also known as voltage stability margin (VSM) depends on the direction of load increase at load buses. In view of this the paper describes a methodology for determining the optimum direction of load increase which gives minimum voltage stability margin. The shortest distance to voltage collapse have been obtained using Sine Cosine and Rao-1metaphor-less algorithms. Results have been presented on standard 6-bus and 25-bus test system