Microgrid protection can be divided into interconnection protection（IP）and inner microgrid protection（IMP）according to its function.The structure and characteristics of IP are highlighted.The IP is classified into three types:system IP，distributed IP and unit IP according to the classification of microgrid.Through an analysis of microgrid load，operation modes and functions，the configuration strategies of IP are proposed.By considering the complicated structure of large-scale microgrid and co-existence of three types of microgrid，coordinating strategies are also put forward.The typical topology of IEEE P1547.4is established in PSCAD/EMTDC in order to verify the feasibility and effectiveness of the protection scheme.