A hybrid AC-DC microgrid: Opportunities & key issues in implementation

Harvesting the maximum possible energy from distributed renewable energy resources (DER) makes the modern electric grid more secure and sustainable. Considering that fact, various technological advancements and government initiatives are initiated to connect this DER through microgrid to utility grid at point of common coupling. The hybrid AC-DC microgrid reduces multiple power conversions in individual AC or DC microgrid and allows connection of variable AC and DC sources and their respective loads simultaneously. This paper illustrates the architecture and energy management of hybrid AC-DC microgrid. Even though, hybrid grid has numerous advantages over individual microgrid, the interconnection of two grids has raised concerns such as complexity, control and protection. Various technical and economical challenges associated with hybrid AC-DC microgrid are also discussed.