With the ongoing transformation of national energy structure

there is a growing trend that large-scale microgrid cluster integrates into the existing power system

therefore

not only microgrid adaptability to network configuration and operational constraints are required

but also new interaction mechanisms both among microgrids and between the microgrid cluster and the upper utility grid should be investigated to improve control flexibility as well as overall economy. In terms of large-scale microgrid cluster integration

we proposed a novel solution for microgrid interconnection and interaction. A further endeavor was made upon reviewing and analyzing the associated key techniques and obstacles which have been spotted in current researches both at home and abroad. Moreover

a typical case study of multi-energy microgrid cluster was given. The results indicate that multi-microgrid interconnection not only enhances system stability via mutual supporting and mutual reserve

but also realizes energy implementation at a broader range and improves microgrid flexibility in providing ancillary services

therefore greatly facilitates their participation in various types of electricity markets.