With the access of a large number of renewable generators to distribution network

the distributed generators based islanding operation has become an important way for the distribution network fault processing. The islanding is the key to realizing islanding operation of distributed generators. The problem of active network islanding is studied from two angles

one the multi-period active power balance and the other the island control mode. Firstly

the research situation of island control mode is put forward. Secondly

considering intermittent distributed power supply and the fluctuation of load demands

an island risk assessment model based on the wind load power curve is established. Then the multi-period dynamic island dividing method is proposed

which can achieve maximizing recovered load while taking into account the island control mode. This method lays the foundation for the realization of the project. Simulation results of a typical distribution network with wind power show the feasibility and effectiveness of the dynamic island dividing method. This work is supported by National Natural Science Foundation of China(No. 51407113)and Shanghai Engineering Research Center for Green Energy Grid-connected Technology(No. 13DZ2251900).