Research On Adaptive Current Protection Based On DG's Power Flow Transfer Area

Traditional power-generation technology causes serious environment pollution problem because of the use of primary energy such as coal and oil.Combined with the deep excavation using of these primary energy,this kind of resource is exhasuted.With the development of west-east electricity transmission project,centralized big power generation mode expands constantly and various of problems arise.Distributed generation attracts people's attention and has a long-term market application prospect because of its flexible,environment friendly and economic characters.With the development new energy and its operation control technology,more and more distributed generations are connected to the distribution network.After that the capacity of distributed generations is bigger and bigger and its influence on the grid attracts people's more attention.Firstly the development situation of distributed generations and adaptive protection is introduced in this paper.While some major power blackout are discussed in this paper.After that the related research are obtained.Secondly,flow calculation and control strategy are handled correctly according to the different characterstics of distributed generation.It takes doubly-fed induction generator as example.Then the regional distribution of the tidal current transfer,the matching of the phase angle and the risk of the line are carried out to find the key dangerous line and the simulation is carried out.Finally the tidal shift factor is only related to the topology of the network.If it could accurately distinguish between power flow and fault disconnection and it could carry out early warning and protection,the sudden tripping of the chain tripping because of distributed generation flow transfer will be prevented from very beginning.A flow transfer factor adaptive backup protection strategy is introduced and it is carried on the simulation by IEEE39-bus system.