%0 Journal Article %T Comparison of Optimized PSS Using Three Different Methods for Single and Multi-Machines Systems %J Journal of Electric Power & Energy Conversion Systems %I Shahed University %Z 2345-4830 %A Horiyat, Navid %A Shariatmadar, Seyed Mohammad %D 2016 %\ 07/01/2016 %V 1 %N 2 %P 60-65 %! Comparison of Optimized PSS Using Three Different Methods for Single and Multi-Machines Systems %K Direct Lyapunov method %K Power Swings %K UPFC %K SMES %R %X Oscillations of power systems cause instability in power networks. Power system stabilizer (PSS) is used as a conventional method to damp these oscillations . Finding the optimized gain of PSS is one of the major problems in power system stability issue. In this paper, single machine connected to an infinite bus and 10-machines 39-bus network are considered for study. it's shown that finding the optimal gain by "theory of optimal control" is more better for stability of power networks than the other methods such as "genetic algorithm" , "electromagnetism-like". This claim is proved using system eigenvalues in the analysis of linear system for both networks. Finally, comparison between these algorithms is also provided. %U https://jepecs.shahed.ac.ir/article_391_d83afb4789522ea905b2ed564e6476ba.pdf