Optimal power sharing of an inverter-based autonomous microgrid

Abstract

Stability of the autonomous microgrids while sharing the power between multiple distributed generation (DG) units is an important task. Conventional droop control is usually used for power sharing between DGs. Power sharing coefficients and controller parameters affect the stability of the microgrid. In this paper, to improve the transient dynamic response of the microgrid, a power derivative-integral term is added to the conventional droop control. The design problem is formulated as an optimization problem. The power sharing coefficients and controller parameters are obtained using the particle swarm optimization (PSO) to achieve the microgrid stability based on power error minimization. Nonlinear time domain simulation is executed to investigate the proposed controller effectiveness for different disturbances. Finally the results show satisfactory performance with efficient transient damping characteristics of the autonomous microgrid.