A procedure to identify an accurate linear model of a synchronous machine

Results of a nonlinear simulation is used in this paper to identify a linear model of a black-boxed synchronous machine. Linear system identification methods such as Prony Analysis, are employed to identify linear models of power system devices when their complete mathematical models are not available to be included in small signal stability studies. While the user lacks the knowledge of the control structure and its parameters, availability of the machine model is practically possible as the models and their parameter estimation methods are well established. Rapidly decaying transients of the machine, such as amortisseur winding transients, usually tend to be missed by available system identification methods. In this work an improved expanding-data-window Prony Analysis method is complemented with an eigenstructure assignment based method to incorporate a-priori knowledge of the generator to determine the highly damped transients of an electromagnetic transient (EMT) simulation model of a synchronous machine with generator controllers.