Research On The Key Issues Of Secondary System Design For500kV Smart Substations

During the12th five-year plan, China State Grid Corp will build about5000smart substations and upgrade1000traditional substations to smartsubstations. With the development of smart grid technology, some newrequirements are put forward in the design of substations. Compared with thetraditional substations, the scope of design and the design principles have beenchanged in smart substations. This paper studies some key issues of thesecondary system in500kV smart substations, including substation networkstructure and configuration, secondary equipment integration and secondarysystem design drawings based on virtual terminal, etc..This paper studies and demonstrates the key technology of substationautomation system structure. And it proposes scenarios about networkstructure and equipment configuration of station control level and processlevel in500kV smart substations. Through the calculation of network flow oftypical interval, this paper optimizes the configuration of network switches. This paper studies the present situation in substation about system network,device configuration and function, suggests some design ideas and methods forsecondary equipment integration. Secondary integration is involved with theequipment function optimization in each specialty and the equipment functionadvantaged complement between specialties. After integration,we can cancelsome repetitive equipments, reduce the investment cost and improve theintelligent level of substations.In smart substations, there have fundamental changes in secondary circuit.Smart substations use fiber-optic network to exchange data. Physical terminalsare replaced by virtual terminals, and the traditional secondary circuits arereplaced by virtual circuits. Intelligent protection devices use GOOSE totransmit interaction and tripping information. The design flow of secondarysystem and the contents of drawings have been changed greatly. This paperanalyses the protection GOOSE information flow of typical interval, andproposes the naming principles of the substation IED, and solves the problemthat GOOSE configuration is difficult to show in secondary system designdrawings.