Dynamical analysis of voltage stability for a simple power system

The nonlinear dynamical systems theory to voltage stability analysis is introduced in this paper. The property that the number of equilibrium points (EPs) varies with operation parameters is investigated, and the stability of every equilibrium point (EP) is explored. A simple and efficient method of locating static bifurcation points is presented. Voltage stability regions of the system are constructed in state space considering the dynamics of on-load tap-changer (OLTC) and load. Finally, the application of the theory to voltage stability analysis is illustrated by time-domain simulation. The work of this paper is essential to the understanding of voltage collapse phenomenon.