Based on the background of Luxi Island microgrid demonstration project

the microgrid characteristics are presented together with the system scale and composition

which consists of wind turbines

photovoltaic (PV) and energy storage. The structure of multi-microgrid with multiple points of common coupling (PCCs) and the monitoring system based on hierarchical control are proposed with an emphasis on 24 operation modes and its switching strategies and process. The operational experiences of mode switching processes are given

and they demonstrate the performance of microgrid seamless switching between the grid-connected and stand-alone modes with the intelligent strategies and flexible structure. They are conducive to improve the reliability of power supply on the island and reduce the possibility of electricity shortage on summer peak load. This work is supported by National High Technology Research and Development Program of China (863 Program) (No. 2011AA05A107).