Towards medium voltage hybrid AC/DC distribution Systems: Architectural Topologies, planning and operation

AC systems have been used for power distribution for more than a century owing to their numerous advantages, which have led to their widespread adoption worldwide. However, the modern world is being rapidly revolutionized by clean, green, and environmentally friendly distributed energy resources (DERs), electric vehicles (EVs), energy storage systems (ESS), and various DC loads. These DC-based smart energy technologies require converters to interconnect with existing AC distribution systems, which are expensive and cause power losses. Recently, the concept of medium-voltage (MV) hybrid AC/DC distribution systems has been proposed for the direct interconnection of AC and DC generation units and loads to the distribution system. Additionally, the MVDC link provides further advantages, such as a higher transfer capacity, reduced power losses, enhanced hosting capacity, voltage regulation, and improved voltage profile. This article presents a detailed and systematic review of architectural topologies with real-world examples and compares different techniques and methodologies for different aspects of the planning and operation of MV hybrid AC/DC distribution networks to attract the interest of scholars. Moreover, future trends and key findings from this review are discussed to stimulate further research and innovation in this area.