A Multi-Port and Reconfigurable Hybrid AC/DC Microgrid Architecture with Hierarchical Power Control for Nearly/Net Zero Energy Buildings

Abstract

As the major energy consumers in the world, buildings contribute to 40% of global energy consumption. Hybrid AC/DC microgrid provides a desirable solution for buildings to improve the energy efficiency, thereby achieving the target of nearly/net zero energy buildings (nZEBs). This paper presents a multi-port and reconfigurable hybrid AC/DC microgrid architecture and corresponding hierarchical control scheme for nZEBs. The central component of this architecture is the new interlinking converter (ILC) called smart interlinking unit (SIU), which is characterized by multiple AC/DC ports, reconfigurable topology and various control functionalities. Besides, a hierarchical control strategy, which composes of local control and power flow control in respective primary and secondary control level, is proposed for this architecture. This control approach could implement a flexible power exchange among AC sub-grid, DC sub-grid and utility grid. Additionally, an improved exploitation and local consumption of renewable energy resources (RESs) could also be achieved. The validity of the introduced architecture and hierarchical control scheme is verified by comprehensive cases.