Power system stabilizer for power sharing control of parallel inverters in a grid — Connected micro-grid system

This paper considers the power sharing stability of a grid connected Micro-grid (MG) system with three Distributed Generation (DG) units via Power System Stabilizer (PSS). Various PSS structures are employed and compared in order to achieve the best transient response under different DG penetration levels. Particle Swarm Optimization (PSO) is used to tune to controller parameters. The optimal controller´s parameters where found by minimizing an objective function that moved the unstable eigenvalues to the left-hand side of the complex s-plane. The PSO based PSS is designed for low and medium of the MG. The results proved the effectiveness of the PSO tuned PSS in stabilizing the power system for the selected operating points.