Abstract
Power system is a dynamic system which 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 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 using the least mean square method. The effectiveness of the proposed method is confirmed through some numerical analyses. The transient stability is evaluated by using the method. The result shows that the region of stability is occasionally narrower than that is evaluated by the classical method.
