Design of Centralized Controller for Efficient Power sharing and Voltage Regulation in DC Microgrid

Abstract

Direct Current (DC) Microgrid systems have gained popularity due to their advantages over Alternating Current (AC) Microgrid systems, including fewer power conversion control stages and the increasing use of distributed energy resources (DERs) and loads. Voltage regulation and active power sharing are crucial for stable and optimal operation in DC Microgrids since they lack frequency and reactive power. Neglecting proper power sharing and voltage regulation can lead to increased power losses and even blackouts. This paper presents a novel centralized controller without droop control, aiming to achieve precise DC bus voltage regulation and efficient power sharing within a fully isolated DC Microgrid equipped with Photovoltaic-Battery Energy Storage Systems (PV-BESSs) and loads. The proposed non-droop-based centralized control strategy modifies the typical primary controller inner current and outer voltage control loops, while a centralized secondary controller generates power/current reference signals for various distributed generators (DGs) and DC converters to facilitate load sharing. This approach offers the advantage of eliminating conventional droop control and secondary controller. The Simulation results substantiate the efficacy and effectiveness of the proposed centralized control strategy in regulating the DC bus voltage and managing dynamic power variations within the Direct Current (DC) Microgrid.