Seamless transition between operating modes in a microgrid cluster

Abstract

Microgrid clusters and their interconnections with utility and among each microgrid provide improved power quality and reliability. Inheriting the capability to operate in island and grid-connected operation, microgrid clusters need a well-structured control strategy to facilitate the microgrid-to-microgrid interconnections and islanded-to-grid transition. This study addresses the challenge by proposing a synchronization architecture for a ring-connected microgrid cluster. Microgrids comprising of several distributed energy resources, are interconnected via a back-to-back power electronic switch. The local synchronization system in each microgrid communicates with the energy management system and controls the parameters of the microgrids to facilitate the synchronization of the microgrids. Microgrid-to-microgrid synchronization is managed by the central controller of the microgrid cluster. The performance of the proposed synchronization architecture is verified using a microgrid cluster derived based on a real distribution system. The results reveal that smooth transition between microgrid modes can be achieved within 7.2 s.