Frequency domain approach for the analysis of power system dynamic stability

This paper describes the application of frequency domain stability and robustness techniques to the problem of power system dynamic (or "small disturbance") stability analysis. The linear dynamic model of the power system is cast into the form of multivariable feedback systems which retain important structural properties of the system. The stability of the feedback systems is determined through the application of the nyquist encirclement criteria to the determinant of the sparse return-difference matrix. The robustness of dynamic stability is defined and primarily concerned, in this paper, with perturbation in the power supply and demand variables. Three approaches are considered for the study of the robustness problem: an optimization-based approach, an approach using recent matrix-norm robustness criteria, and an approach using stability and robustness results for the componentconnection model. A number of power system examples are given in the paper.