Design and Control of Smart DC Microgrid for Integration of Renewable Energy Sources

This paper presents the design, modeling, and operational analysis of an autonomous coordinated control strategy for a "DC microgrid" in islanded mode under various loading conditions, with and without Battery Energy Storage System. The DC Micro-Grid (DCMG) consists of Wind Turbine (WT), Solar Photo Voltaic (SPV), Solid Oxide Fuel Cell (SOFC) generators, dc and ac (three-phase and single-phase) loads. A three-phase bidirectional PWM VSC (ac-dc) is used for integrating WT to DCMG, which establishes constant dc voltage. In case of failure of this VSC, dc-dc boost converter employed for integrating SPV, has been utilized for establishing constant dc voltage. The SOFC generation is also integrated to DCMG through a dc-dc boost converter, which is controlled to maintain the power balance in the DCMG depending on the rated plant capacity and peak power capacity of the SOFC generation. The design, modeling and simulation of the proposed control scheme for the DCMG have been implemented in MATLAB/Simulink environment.