A suitable selection of hybrid compensation can improve the power transfer capability and voltage regulation of long transmission systems. In this paper, hybrid compensation is realized by a combination of fixed series capacitor and shunt active FACTS controller STATic Synchronous COMpensator (STATCOM). The objective is to investigate the subsynchronous resonance characteristics of the hybrid compensated power system and propose a simple method for the extraction of subsynchronous component of line current using filter. The extracted subsynchronous frequency component is injected by the STATCOM at PCC, prevents the flow of subsynchronous current through the generator, and increases the damping of the system at critical torsional frequencies. This novel technique is termed as Subsynchronous Current Injection. The design of Subsynchronous Current Injector is based on damping torque analysis and Genetic Algorithm. The study system is adapted from IEEE First Benchmark model. The results show the effectiveness of the proposed Subsynchronous Current Injector in damping SSR. The SSR characteristics are analyzed based on linear analysis methods and nonlinear transient simulation. Linear analysis includes, Damping torque and eigenvalue analysis, which uses D-Q model of the system. The results of linear analysis are verified by performing transient simulation with detailed nonlinear model of the system. © 2011 Praise Worthy Prize S.r.l. - All rights reserved.