The Effect of increasing penetration of full converter controlled-based generators (CCBGs) in a large scale power system is evaluated by using MATLAB program based on small signal stability analysis. The power system has been subjected for two types of tests, the first test has been implemented by disturbing the system through applying 3-phase fault at the infinite bus system, and the second one by increasing the mechanical torque of the system. Both of these tests have been applied under three cases of the penetration ratio of CCBGs in the system. The first test has been done without any penetration of CCBGs, the second one with a relatively small ratio of CCBGs penetration which equal 20%, and in the third case the penetration level has been increased greatly up to 40% of the total generation in the system. The contribution of CCBGs and their interaction with the other traditional electromechanical modes have been analyzed. The conventional power system stabilizer type which is a lead-lag power system stabilizer (PSS) has been used in order to overcome the oscillation problem that occurred due to these type of disturbances. Also the Linear Quadratic Regulator (LQR) method has been adopted, and the results showed that it is very effective way to reduce the oscillation frequency problem and return the system back to its steady state condition.