A generalized energy function for transient stability analysis of power systems

In this paper, an "energy function" is derived for transient stability analysis of power systems. The main contribution of this paper is the generality of the model for the loads. The loads are modeled as constant real power loads but the reactive part of the loads are modeled as arbitrary function of the load bus voltage. This model accounts for the voltage transients of the load busses and for this general model, it is shown that the system satisfies the law of conservation of energy. An efficient algorithm for determining the stability of the system for a given disturbance is described. Results of simulation of the system studied by El-Abiad and Nagappan [2] are included and it is shown that due to the fluctuations in the system voltages, the commonly used energy function over estimates the energy of the system during system transients.