Several factors have led to weaker grids and a greater need for power quality. These include the rapid spread of distributed generation, multi directional power flows, increased electricity consumption and generation capacity, long distance bulk transmission, and fewer synchronous machines connected to the power systems. Modern power systems experience low fault currents, narrow reserve margins and limited inertia contribution. To face these challenges a Static Synchronous Compensator (STATCOM), one of the most wide spread Flexible Alternating Current Transmission Systems (FACTS), can be involved. The main objective of this thesis is to analyze how the integration of a STATCOM enhances the performance of non stiff power systems.