A Higher-Order Newton Method Approach to Computing Transient Stability Margins

A new iterative procedure for accurately computing the transient stability margin of multimachine power systems is presented. The approach is based on a variant of a Newton´s method with higher order convergence and enables the transient stability margin to be determined with respect to a particular contingency or variation of a critical system parameter. A general technique for the computation of transient stability margins is suggested. In this procedure, the system dynamic behavior following a given perturbation is represented by a time-varying one-machine infinite bus equivalent. Using trapezoidal integration and polynomial approximation techniques, the equal-area criterion conditions are transformed into a form suitable for nonlinear analysis of the critical stability margin. By combining the extended equal area criterion with higher-order Newton-type techniques, a method is then proposed to compute the transient stability margin. The accuracy of the proposed method is verified through simulation studies on a large, realistic power system model. Preliminary results of the application of the proposed technique to the calculation of critical clearing times and critical loading conditions of a large power system are presented and discussed.