Distributed Topology Storage And Management Method For Smart Distribution Network

In distribution automation system,the topology information is one of the important basic information,generally taking centralized storage and management methods,by the dedicated server to complete the corresponding function.The centralized storage and management of topology information has the advantages of intact and easy to manage and to maintain,but there are also strong dependencies on the management server.The centralized methods also have many shortcomings,such as the strong dependence on the management server,topology information update is slow and less flexible,and the topology often does not correspond to actual system.The current distribution network is running complex and has many branches.At normal operation,the system scheduling needs to collect,detect the whole network data,receiving and sending a large number of instruction information.When the fault occurs,the system needs to combine the topology to quickly and accurately diagnose and isolate the fault.In recent years,the distributed protection and control system has been paid more and more attention in the smart distribution network.The distributed system has high flexibility and adaptability,which is more in line with the structural characteristics and operating requirements of the intelligent distribution network.In the distributed system,the system is not suitable for the centralized topology information storage and management.So,it is necessary to study the distributed topology information storage and management method,which is suitable for the structural characteristics and functional requirements of the distributed system.In this paper,based on the predecessors,the article presents a distributed topology storage and management method for protection and control system of smart distribution network.Each distributed smart terminal unit(DSTU)only needs to configure the basic topology information of the installation.Through the development of the orderly broadcast communication strategy,it can automatically obtain the access of the adjacent distribution terminal information and the division of the topology logical layers,realize the local topology identification.The local topology can support protection and control functions.Based on the local topology recognition result,the topology minimum connection tree is generated,and the minimum connection tree is used as the basic unit to determine the agent unit.A simplified method of topology based on agent is proposed,which provides a topology information acquisition and management method for the functions that requires large-scale topology information.Taking the distributed fault self-healing system as an example,the application of distributed topology storage and management method of smart distribution network is analyzed.First of all,the article describes the distributed control strategy,including the basic ideas of topology information storage and management,and distributed communication strategy.(1)In the distributed system,there is no centralized server to store and manage the whole network topology information.By the storage and computing power constraints,DSTU is impossible to replace the centralized server on the whole network topology information storage and management.Therefore,the topology information of the whole power network can be decomposed into multiple local topology information according to the installation and configuration of DSTU.Each DSTU stores only related local topology information.DSTU can also interact with other DSTU to exchange topology information to provide topology support for various functions of the distributed system.(2)At the same time,the distributed communication strategy includes broadcast communication and point-to-point communication,in which broadcast communication can be divided into initial broadcast and online broadcast.The article defines the trigger conditions,application categories,communication strategies,termination conditions of various communication methods.After the DSTU is powered on,each DSTU performs an initial broadcast to identify adjacent terminals according to the broadcast strategy.After the adjacent terminal is determined,the system adopts peer-to-peer communication to complete the interaction of the relevant information such as the position of the switch.If there is a new smart terminal input or terminal removal,the terminal uses the online broadcast to inform relevant equipment.Secondly,the paper presents specific method of distributed topology information storage and management,which can be divided into two parts:The first part includes the identification of neighboring nodes and the storage of local topology information.In the initialization phase,the basic topology information is configured for each DSTU according to the specific structure of the distribution network.This information contains only the node information at the DSTU installation location and the corresponding branch information,and does not contain the adjacent DSTU.After the DSTU is powered on,it will perform initial broadcast according to the strategy,divide the logical layer,and identify the local topology information of the adjacent DSTU.When the external topology changes,the relevant information will be refreshed automatically to ensure that the local topology information consists with the actual topology structure.The second part includes the online division of agent nodes and the simplification of topology information.Based on local topology information,DSTU determines the agent nodes,simplifies the whole topology.This paper provides an interactive method for distributed systems with large range of topological information,which improves the reliability and efficiency of topology information between DSTUs.To this end,the article defines the agent nodes online strategy,and the management scope of the agent nodes and the other relevant information.Finally,a typical distribution network is taken as an example to analyze the application of distributed topology storage and management method in fault self-healing system.The example consists of two parts.The first part is the generation process of distributed topology information.The second part is the application of topology information in fault detection and isolation,fast island detection and operation control,fast power supply recovery and so on.