Cost-Effective and Retrofit Solution Control Algorithm of Renewable Fed DC Microgrid System

Abstract

DC microgrids (MG) provide efficient integration of renewable resources, storage capabilities, and load distribution into the electric power system, which makes them superior to AC MGs. Different power sources such as wind turbines, distributed energy resources (DER), photovoltaic (PV), and battery energy storage systems are considered to supply the load demand. In the present environment, when enormous amounts of renewable energy are being injected into the electrical system oscillations caused by load or source transients and energy management should be ministered appropriately, as per global standards. Supercapacitors are efficient energy storage devices that can function as ESS in a droop-regulated DC microgrid in order to compensate for the ups and downs in the DC bus voltage brought on by the load demand and DER integrations. The control schemes, droop control, master-slave control, and other distributed and hierarchical control techniques, have several advantages and disadvantages with regard to cost-effectiveness, complexity, and resilience. A novel microgrid control technique is proposed as part of this work, where a piecewise droop control mechanism is introduced in order to utilize the surge power handling capability of supercapacitors to address the aforementioned voltage swings. The proposed method is evolved by combining features of the conventional droop method and the DC bus signaling mechanism. Simulation studies performed with the proposed control indicate predominant improvement in the system characteristics, whose results are presented in the later sections.