Research And Application Of Digital Substation Technology In Substation Reformation

With the development of science and technology, digital substation has been the developing direction of substation technology. Digital substations have distinct stricture and highly automatic level, and they are convenient fot maintain. Reforming traddition substations to digital substations have been a hot research field. On the basisi of analyzing amount of documents, this paper compares the advantages of digiyal substations compared with tradditional substations, analyzes the structure of digital substations. Observed from point of structure, digital substations have the structure of three layers and two networks, i.e. station control level, bay level, process level, process level network and bay level network. Observed from point of technology, features of digital substations are digital sampling, hierarchical system, compact system structure, standard system modeling and stated equipment maintenance.This paper discussed key technologies of digital substations, including intelligent circuit breaker, non-conventional instrument transformer, merge cells and IEC61850 protocol. This paper analyzes working principle of intelligent circuit breaker, and points out problems possibly occurred in actual application; introduces non-conventional instrument transformer, states the connecting problems between merge cells and secondary units, introduces IEC61850 protocol.This paper proposes digital reforming scheme. Firstly, whole scheme is introduced; then solutions for network communication part, substation level, process level, intelligent units and circuit breakers are analyzed. Finally, Hefei plant garden substation is taken as an example. Its operating scheme is analyzed and advandages, economic and social benefits after reformation are analyzed.