An application of energy function with nonlinear load models for calculation of critical fault clearing time

This paper presents an application of energy function with included effect of nonlinear load models to be incorporated for the calculation of critical fault clearing time, which can be used in the analysis of maintaining power system stability. The conventional transient stability studies have used time domain to find critical fault clearing time for clearing machine under fault condition is not practical because it uses the trial-error method. Energy function methods are used to find the critical fault clearing time, which is superior to the conventional method (time domain approach) in term of computation time. The method is calculated the potential energy boundary surface (PEBS) and the controlling of unstable equilibrium point (CUEP). The system load model is developed which is included non-linearity of power system load. The non-linear load models are made to yield an accurate result more than constant impedance load model.