Bifurcation analysis of power systems with tap changer

Abstract

A bifurcation analysis of nonlinear dynamics for electric power system with tap changer is presented in this paper. Based on a model of electric power system proposed by Dobson and Chiang (1988) with one extra tap changer added parallel to the local nonlinear power load, the saddle-node bifurcation and Hopf bifurcations are observed by treating the real power, reactive power and tap changer as system parameters. The occurrences of subcritical Hopf bifurcation and saddle-node bifurcation lead to the appearance of dynamic and static voltage collapses, respectively. These phenomena may generate the progressive decrease in voltage magnitude in electric power system.