Choice of FACTS device control inputs for damping interarea oscillations

A method is proposed in this paper to select the input signals for both single and multiple flexible ac transmission system (FACTS) devices in small and large power systems. Different input-output controllability analyses are used to assess the most appropriate input signals (stabilizing signal) for the static var compensator (SVC), the static synchronous compensator (SSSC), and the unified power-flow controller (UPFC) for achieving good damping of interarea oscillations. The study presented in this paper is carried out on one small system with one FACTS device at a time; and one large system equipped with the SVC, the SSSC, and the UPFC.