A Practical Double-Parameter Steady Voltage Stability Boundary Tracing Method

The interaction and nonlinear relationship between different parameters or groups of parameters always are interested by the operators in control center of power grid. A practical tracing method of two parameter stability boundary for voltage stability assessment is proposed. In the traditional tracing method of two parameter bifurcation boundary a second order Hessian matrix of power flow equations has to be computed and factorized, which is a difficulty for on-line application of a large scale power system. By using the single parameter trajectory tracing and the bifurcation point seeking and identification alternately, with the computational expenses of some additional points, the proposed method handles the Jacobin matrix and overcomes this difficulty. The preposition of the proposed method is that the interested part of two parameter stability boundary is composed of both the saddle node bifurcation points and the limit induced bifurcation points, without double saddle node bifurcation points. It is satisfied since the interested part of the boundary is limited. The numerical results about a 3187 bus actual system show that the proposed method is very efficient for on-line application.