Research On IEC61850-Based Communication Technology For Distribution Automation

With the development of distribution automation and the proposition of smart distribution network, many problems in the construction and running of distribution network attract more and more attention. The distribution terminals have a great quantity and extensive dispersion. The various communication protocols coexist in the distribution network and the interoperability is poor, it is difficult to maximize the functions of distribution automation. IEC61850provides a unified standard for the substation automation systems, could resolve interoperability issues very well. The paper introduces the IEC61850to the distribution automation, guides the modelling of distribution equipments, specifies the used communication protocols, resolves the communication problems, realizes the Plug and Play and reduces the maintenance workload. The specific studies include:(1)The paper establishes the information models of distribution terminals. The functions and the structure of distribution automation are analyzed, and the contents and technical characteristics of IEC61850standard are described in detail. The Poled-mounted switch FTU is taken for example to introduce the object-oriented unified modelling method. First of all, to analyze the functions and to decompose the functions to the corresponding logical nodes; Second, to compose the logical device with the logical nodes to complete the device modelling; Finally, to realize the self-describing of device model by the configuration file.icd. In this way, the communication bodies can understand each other’s information without prior agreement, only by obtaining the configuration file. This builds the good base of the interoperability.(2)The paper realizes the Web Services mapping of information model and service model. The common communication protocols in distribution automation and the current researches of the IEC61850mapping are analyzed. Though the researches of mapping to IEC60870-5-101/104are rich, many questions still exist. These communication protocols are the planar structure, can not exist independently without the communication rules, and can not realize the mapping of the parts of service model that emphasis on the description of information model. The IEC61850mapping to Web Services is raised through researches of the technical characteristics of Web Services, the development costs and the good support of information model and service model. The specific mapping principle is raised by reference to IEC61400-25-4standard, includes information model mapping and service model mapping. Through in-depth analysis of Web Services, an implementation plan is proposed. The article focuses on the analysis of directory services and reporting services, and uses the gSoap toolkit to achieve the web communication in the software design.(3)A test system is developed, includes distribution terminals and manger machine. The test of web communication between them shows that the correctness and timeliness of its response can meet the requirements of the distribution automation and proves the feasibility of the mapping.The device modelling in distribution automation can help build a unified information model of the power system, achieve information sharing. The Web Services mapping method can realize the communication between equipments very well, and has much referential value for the similar application. The open communication architecture based on IEC61850can promote the construction and development of distribution automation and smart distribution network.