A Grid-Connected Smart Extendable Structure for Hybrid Integration of Distributed Generations

In this paper, a novel grid-connected smart and plug-and-play type extendable structure named unified multiport power electronic converter (UMPEC) for hybrid integration of distributed generation (DG) systems is presented. The proposed structure contains two types of connector ports. The first one is a set of AC connectors, which can be easily used to connect different types and numbers of AC-based DGs along with grid and loads. The second one is a set of DC connectors, which can interface DC-based DGs and storage units. Compared with the conventional and recently invented multi-stage power electronic topologies, the proposed structure enjoys less number of power electronic components, compactness, and plug-and-play capability of integrating AC and DC-based DGs. Considering shared components between different ports and their imposed boundaries on the operation of the UMPEC, a modified sequential space vector modulation is addressed, which makes it possible to control different ports independently, without compromising with maximum power harnessing from individual sources, which is another salient feature of this work. The proposed structure operation and performance is verified using a three DC and two AC connectors version, where wind and photovoltaic systems are independently interfaced to the grid.