Non-linear approaches for reducing large power systems

Issues on the establishment of equivalent networks are becoming essential f or the deregulated power market. This paper presents a comprehensive tool f or network reduction of large power systems. Through integrating different methodologies into a simulation program, the dynamic equivalent can be esta blished by adopting one common database. With a readily integrated modified Gauss-Newton algorithm, network reduction can be executed tinder the dynam ic conditions either in the time domain or in the frequency domain in copin g with nonlinear nature of the system involved. Furthermore, a novel algori thm based on dynamic coherency approach implemented readily into the simula tion program is also presented. This novel approach determines coherent gen erators on non-linear basis in the time domain using the cross correlation technique, taking dynamic characteristics of the system involved into consi deration. Two case studies are presented in this paper. Each of the non-lin ear approaches presented is applied for one of the case studies as applicat ion example. The results achieved validate the functionality of the approac hes presented.