A DC Power Exchange Highway Based Power Flow Management for Interconnected Microgrid Clusters

In this paper, the concept of dc power exchange highway (DCPEH) is introduced to interconnect a cluster of ac microgrids (MGs) to facilitate an efficient and resilient energy system. A power flow controller is proposed to manage the power flow between an MG and DCPEH, based on local load demand, surplus power, and power shortfall of an individual MG. This control integrated with DCPEH will improve the resiliency and reliability of MG clusters by utilizing the maximum available power from uncertain distributed energy resources (DERs) like solar or wind energy conversion systems in individual MGs. Each MG is connected to the DCPEH through an active front-end converter and a storage capacitor. The converter holds the dc voltage at a pre-defined value. A dynamic droop control for the DCPEH is adopted to effectively distribute the power demand between MGs. In this paper, it has been assumed that the cluster operates autonomously with the presence of a utility grid. It has been further assumed that the MGs are dominated by converter interfaced DERs, and hence, the power sharing is performed using angle droop control. To verify the efficacy of the interconnected MG clusters using DCPEH, various simulation studies are conducted using power system computer aided design electro magnetic transient design and control.