Abstract

The increasing demand for energy and the high penetration of distributed energy resources require the evolution of current electrical systems toward smarter and more reliable electric grids. In this regard, microgrids (MG) play a vital role in integrating distributed energy resources (DER), loads, and storage systems. However, microgrid architectures lack versatility and flexibility in terms of control, limiting their expansion. This paper presents a multi-mode master-slave control approach to increase the flexibility of DC-coupled hybrid microgrids. The proposed control scheme allows optimal coordination of the power units connected to each bus. Coordination among buses is also achieved through interlinking and interfacing converters; thus, ensuring the reliable operation of the microgrid. Moreover, this approach considers the possible expansion of the capacity of the MG, providing more degrees of freedom for optimization and control. An MG with two DC distribution buses connected to the main grid is selected as a case study to develop dynamic modeling and establish a control architecture. The advantages of the proposed control are discussed via MATLAB simulation results considering the operation of the MG in several scenarios.