Research On Reliability Evaluation Method Based On Topology Analysis Of DC Distribution Network Equipment

With the increasing demand for new energy and the advancement of power electronics technology,the advantages of DC distribution network in accepting distributed energy,improving power quality and reducing losses are becoming more and more obvious,and it will become an important mode of distribution network construction in the future.Compared with the AC distribution network,the DC distribution network has invested a large amount of power electronic equipment on the one hand,which has increased the complexity and failure rate of the equipment,and has a greater impa ct on the reliability of the power system.on the other hand,DC distribution network contains distributed power,load point power supply paths increase,and DC does not need to consider reactive power and electromagnetic loop network issues,so that the topology of the DC distribution network has a complex type such as a ring network,and most of the reliability evaluation methods of traditional distribution network are difficult to apply.Therefore,it is of great significance to study the reliability evaluation method of DC distribution network.The equipment and topology of DC and AC distribution systems are different,and the emphasis of reliability evaluation is also different.Firstly,this paper summarizes the research status of reliability of AC and DC distribution systems.On the basis of the traditional minimum cut set method,considering that the reliability of DC distribution network is greatly affected by the reliability of equipment at the present stage,an improved minimum cut set evaluation method considering component activity faults and distributed generation is proposed.Then,the reliability model of key equipment in DC distribution network is established.Three kinds of topological structures of DC circuit breaker are analyzed and compare d,which provide equipment selection and reliability parameters for reliability evaluation of DC distribution network.Finally,the three topologies of the DC distribution network are compared.Taking a hand-in-hand demonstration project of DC distribution network in an industrial area of Shenzhen as an example,the corresponding radial and circular DC distribution network is designed quantitatively.The reliability of three topological structures of DC distribution network is compared.