Power System under consideration consists of the single machine connected to an infinite bus (SMIB) through a tie-line. In the SMIB representation, the dynamic interaction between the various machines in the power station is not considered, but it is still adequate for many types of studies, especially when the machines are identical and operate at nearly the same load levels. .A PID controller along with PSS is used for the better results than PSS alone. Analysis of a large interconnected power system is time consuming and may even exceed the storage capacity of modern fast computers because high order model is costly. Therefore a low order linear model will be derived for high order system to obtain optimized design of controller. Results for both the controllers are shown separately in this paper.