Distribution network protection and automatic device cooperating method based on DG characteristics

The invention discloses a distribution network protection and automatic device cooperating method based on DG characteristics. According to the method, action levels are divided into a fault isolation level, a spare power automatic switching intercutting DG level and a low-frequency low-voltage intercutting partition islet level in space, whether an islet is allowed to operate or not is determined according to the balance capacity of DG local loads, and fast islet division is achieved automatically through a low-frequency low-voltage intercutting fixed value to guarantee stable operating of a power system and reliable operating of the local loads. Meanwhile, a protection fixed value considers that even though DG is in an islet operating state and breaks down, a protection device can act fast and accurately to remove the fault. Regional information is adopted as coordinating factors and is used for overcoming the defects of separation of a relay protection and automatic device and a DG operating work condition, division of the islet extending layer by layer is determined according to the trend distribution of a power source and loads after fault current removing and the changes of a network topology structure, and a coordinating distribution type power source protection scheme system is formed.