To maintain the stability of the power plant system, effort are needed to keep the generator in sync. This study was conducted to determine the performance of each power plant in the Sigura-gura power system when interference with the transmission network. By reviewing the response curve through simulations with the EDSA software, it can be seen the changes in rotor angle, voltage oscillation and power for each generating system when a disturbance occurs. The application of PSS as a compensation to improve the character of the power system’s stability against interference by observing changes in rotor angle, voltage and power. The observations show that the installation of PSS controllers in excitation as compensation to the Sigura-gura electric power system can contribute to better system performance by improving the rotor angle oscillation time, voltage and overshoot respectively 7.8%, 66.6% and 37.9%.