Technical challenges of integrating high proportion distributed photovoltaic power into medium DC grid

With rapid development of distributed photovoltaic (DPV) in most regions, integrating into medium DC power grids is a new efficient way to increase new energy consumption, while the research and engineering practice in this field are still at the initial stage. Based on the instance summaries of completed project, the challenges of integrating high proportion DPV into medium DC grid can be summarized as follows: Topology design with multi-port converts used, critical electronics equipment development used in MVDC, stability analysis of large amount of electronics components interaction with insufficient of traditional method, absence of standards for integrated design guiding practical projects. Considering the economic and technology factors given, three topologies with proposed multi-port converters are given. Besides usual stability analysis methods based on the impendence and state space, applicability of little or large single analysis are discussed. Further studies that can be conducted relevant to high proportion of DPV integrating into developed MVDC system are finally proposed. All these researches can be possible reference for the studies being implemented by the author's team.