A method for analysis of dynamics in generator swing based on nonlinear system theory

A power system is a dynamic system that includes several kinds of nonlinear elements. According to nonlinear analyses using the Hopf bifurcation theory, it is detected that a limit cycle exists around an operating point, which may affect the stability of the power system significantly. This paper presents a numerical method to analyze the nonlinear characteristics in power systems by observing the power swing after some perturbation where the coefficients of nonlinear terms are determined by the least mean square method. The effectiveness of the proposed method is confirmed through some numerical analyses. The method is used to evaluate the transient stability. The result shows that the region of stability is occasionally narrower than the region evaluated by the classical method. (C) 2000 Scripta Technica, Elects Eng Jpn, 134(3): 16-25, 2001.