The Reliability Evaluation Of The Distribution System Containing The Distributed Generator

With the development of economy and society,the demand of people on powerquality is further more.The reliability of power system is one of the key factors ofpower quality.Distribution system is the trip of power syatem,and connects to theconsumers. According to statistic，the80％of outage events due to the failure ofdistribution system.Nowdays,under the force of environment issue and energyissue,more and more attention are paid to the reliability of distributed generation.Withthe penetration of distributed generation, distribution network’s operation manner andconstruction is greatly changing. So it is important to study the impact of DG on thereliability of distribution networks.Island is a new kind of operation mode when the distribution network isincorporated with DG. Once a fault happened in a feeder,reasonal intentional islandingis very important. Because of the fluctuation of the distributed generator’s output,thispaper uses a4-state-model,and makes use of the short-term analysis to cope withthese problems and we achieved the reliability evaluation of the distribution systemcontaining one distributed generator. Then the paper validates the importance of loadsin power network and builds a separation islanded mode method, with the maximumof equivalent loads as the aim of function，at the same time,the mathematical model isobjected to some security constraints.This paper proposes rooted tree and thealgorithm of search and verification to search the reasonal island.Because of theisland,it is needed to make a new version of the minimal path method in thetraditional assessment analysis to suit for the algorithm considering the DG. AnIEEE-RBTS Bus6system is applied to testify the efficiency of the modified model.The case results show that DG can increase the reliability of distribution system,andalso it dellonstrates that the distributed generation has the ability of improving thereliability of system and customers.