%0 Journal Article %T Fault Detection Based on Observer for Nonlinear Dynamic Power System %J Energy and Power %@ 2163-1603 %D 2012 %I %R 10.5923/j.ep.20120202.02 %X In this paper, the fault detection problem for nonlinear dynamic power systems based an observer is treated. The nonlinear dynamic model based on differential algebraic equations (DAE) is transformed in to ordinary differential equations (ODE). Three nonlinear observers are used and compared for generating the residual signals. Which are: the extended Kalman filter, the extended Kalman estimator and the relevant version of extended Kalman filter with a moving horizon within a study of convergence based on the choice of covariance matrix of the system noises and measurements. The paper illustrates a simulation study applied on IEEE 3 and 13 buses test system. %K Fault detection %K Power system %K Extended Kalman Filter %K Moving horizon %K convergence analysis %U http://article.sapub.org/10.5923.j.ep.20120202.02.html