Hybrid system view of voltage instability problem

After approximating the nonlinear of the system used in the analysis of the voltage instability problem, the components models in the system are built. And based these models, it is pointed out that voltage instability problem incorporate not only nonlinear dynamics but also discrete events and some of the manipulated variables are discrete, too. Therefore, the characteristics of the problem are hybrid in the nature. Voltage instability problem can de described effectively by hybrid system model. And it is proposed to analyze the problem by the hybrid system of differential, switched algebraic, and state-reset (DSAR) model.