Fast Determination of Saddle-Node Bifurcations via Parabolic Approximations in the Infeasible Region

This letter presents a simple methodology to quickly obtain the saddle-node bifurcation points of power systems by first solving a sequence of power flows that ends in the infeasible region and then performing a parabolic adjustment with the results of two infeasible cases. The proposed method exploits the ability of the factored load flow procedure to converge to complex solutions well beyond the maximum loading point. Test results on benchmark cases show that the new method yields a significant reduction in the computational cost, when compared to the previous approach based on exhaustive bisection search.