Application of modal analysis for the enhancement of the performances of a UPFC controller in power oscillation damping

The aim of this work is to investigate and evaluate the performance of UPFC (unified power flow controller) devices operating in a transmission system in order to control inter-area power oscillations originated by small disturbances. Particular emphasis is given in using the participation factor matrix in order to identify the state variables which mostly affect the modes of inter-area oscillations and to intervene on those state variables directly related to the FACTS action. The efficiency of the method is subsequently assessed by means of detailed dynamic simulations.