A Modified Redundancy-Based Energy Management System for Microgrids: An SoC Enhancement Approach

This article proposes a dc microgrid (MG) composed of a cascaded bidirectional Cuk converter (CBC) connected to a cascaded bidirectional boost converter (CBB) sharing two battery energy storage systems (BESSs) as common inputs. Then, the dc-link from CBC also receives a boost converter, which interfaces the dc utility. Thus, this configuration can coordinate the BESSs and the dc utility by employing the state-of-charge (SoC)-sharing function and the droop controller. In this context, the combination of CBC and CBB can improve the reliability of the SoC-sharing function with the battery-to-battery equalization on CBB and can enhance the availability of power production on the CBC dc-link. Therefore, the main advantage of the proposed method is to ensure the SoC equalization even when the MG is under maintenance or electrical fault. Additionally, the dc MG involves a modified energy management system while Lyapunov's indirect method proves the stability analysis. Finally, the experimental setup validates the feasibility of the proposed approach.