The weighting Q and R in the optimization process and PSS parameters are important components of the multimachine power system. To improve the performance of power system, this paper presents new strategies of control. The strategy-1 tunes the optimal PSS paremeters using the generic algorithm (GA) calculation through LQ optimal control equation solution as an objective funciton. The strategy-2 develops strategy-1 through a modification of inverse-square method (ISM) ti design the weighting matrices. The strategy-3 uses the special GA to handle the duty of ISM by using the modification of a mutation process. In the last strategy, the initial chromosomes are created from ISM. Using these strategies, the application of multi-PSS and a conventional PSS are applied in the multimachine power system as comparison study. In the final, the strategy-3 has shown the best effort for power system behaviors improvements. It shows that convergences of GA has great improvement in theri penalty evaluation, in eigenvalues and settling time analyses. Keywords: power system dynamics and control, optimal control, inverse square method, genetic algorithm. Imam Robandi; Department of Electrical Engineering, FTI ITS, E-mail: robandi@ee.its.ac.id
