Robust Power System Stabilizers Design Using Multi-objective Genetic Algorithm

Optimal locations and design of robust multimachine power system stabilizers (PSSs) using heuristic algorithms is presented in this paper. The tuning of PSS via a non-dominated sorting genetic algorithm (NSGA-II) is performed to obtain a set of compromise speed-damping solutions. The stabilizers are tuned to simultaneously shift the lightly damped and undamped electromechanical modes of all plants to a prescribed zone in the s-plane. A multiobjective problem is formulated to optimize a composite set of objective functions comprising the damping factor, and the damping ratio of the lightly damped electromechanical modes. The problem of robustly tuning of the power system stabilizers is solved by a nondominated sorting genetic algorithm (NSGA-II) with the eigenvalue-based multiobjective function. The efficacy of this technique in damping local and inter-area modes of oscillations in multimachine power systems is confirmed through nonlinear simulation results and eigenvalues analysis.