A new islanding method for distributed generation and its application in power system restoration

Intentional islanding is an effective method to improve power supply reliability and fully strengthen the role of DGs. A strategy based on intentional islanding for using DGs in the distribution network restoration service in the context of smart distribution network is present in this paper and the restoration procedure of distribution network with DGs is also enunciated. Through the compare and research of existing distribution system islanding algorithms, the objective, principle and algorithm of intentional islanding are studied in detail based on the closed-loop design and open-loop operation characteristics of complex distribution network. An algorithm based on Minimum spanning tree and dynamic programming method is proposed, which can adapt to complex distribution network with the structure containing rings and ensure the restoration of important loads to the maximum extent. Using this method, it can ensure stable operation of islanding and quick synchronization with the upper power grid. The data structure, parameter setting and mathematical representations of the algorithm are introduced. Case analysis on typical islanding is shown to Confirms the feasibility of this method.