Research Of The Relay Protection Of The Distribution Network With DG

With shortage of energy day after day, distribution power (DG) which is as a newpower generation model by using some renewable get more and more attention ofmany countries all over the world. DG can play a role in saving resources, cutting thepeak and valley, reducing the stress of transmission equipments and lines loss,improving the reliability of the power supply and so on. However, the distributionnetwork with DG will be changed from the single power to the multi-power supplied.The direction of the flow is no longer single, and in addition, DG’s retreatingfrequently and the changing of the operation mode of the distribution network can haveeffects on the traditional protection of the distribution network.This paper firstly based on the principle of the traditional current protection,analyzed detailedly that the different of the DG’s capacity and location had the effectson the three-section current protection, automatic reclosing and feeder-terminal-unit bytheoretical derivation and graphic compare, and had on a model-simulation byMATLAB/SIMULINK software. Next, this paper put forward the new setting principleand the improvement methods of the different protection in the distribution networkwith low DG. Finally,this paper based on the distribution network with high DG putforward two new protections, which are the network protection scheme based on theequality communication and the distributed intelligence protection based on themulti-agent technology, and proved the feasibility of these methods by analyzing itsprinciple, summarizing its processe and example simulation.These methods havecertain adaptability, the fault tolerance, good practical value and certain theoretical,which will provide certain references for the development of the intelligent power grid.