This dissertation presents a preliminary research abouth the Generalized Compensator operation at power systems, proposed in Gyugyi [1990], into the scope of Flexible AC Transmision System studies. This study makes a description of the proposed equipment actuation at a two bus system and explains some of its qualitative effects. Two configurations weree chose: a radial with passive load and a system with infinite bus in order to study power interchange between two systems. The voltage-sourced inverters of Generalized Compensator are modeled by voltage and current contrlolled source. These sources operate at the fundamental frequency and at the steady state. The leakage impendances of the coupking transformers are not considered but they will be considered in future researches. Important results are obtained about the new control modes of the transmission system. These new control modes are impossible with the traditional compensation equipament that have been used up to now.