Reduced Order Modeling of Interconnected Multimachine Power Systems Using Time-Scale Decomposition

Time-scale decomposition is used to systematically produce improved reduced order models of interconnected multimachine power systems. The method is illustrated with two fundamental examples. The first shows that the I = YV interface equation used for studying multimachine electromechanical transients is a zero order representation of the fast network transients. As such, the time-scale theory can be used to produce improved electromechanical models without adding the network transient equations. The second example shows how linear models for small change stability analysis can be improved to virtually any degree of accuracy. The advantages of the improved models are shown with both a two- and three-machine system.