Optimal Design of Multi-Machine Power System Stabilizer Using Genetic Algorithm

Abstract

Power system stabilizers (PSSs) are used to generate supplementary control signals for the excitation system to damp electromechanical oscillations. This paper presents an approach based on genetic algorithm for tuning the parameters of PSSs in a multi-machine power system. 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 performance of the proposed PSSs under different disturbances, loading conditions, and system configurations is investigated for different multi-machine power systems. The non-linear simulation results are presented under wide range of operating conditions; disturbances at different locations as well as for various fault clearing sequences to show the effectiveness and robustness of the proposed PSSs and their ability to provide efficient damping of low frequency oscillations.