Research On Secondary System Design Of 66kV CHAAN Intelligent Substation

As an important support and cornerstone of smart grid,Smart Substation is closely linked with other parts of the grid.Smart substation is not only responsible for collecting the operation data of power grid as the source,but also the command execution unit of power grid data.It guarantees the high quality,strong,safe and economic operation of smart grid.The design of secondary system of intelligent substation is the most important,and it is also the most fundamental difference between intelligent substation and conventional substation.In this paper,combined with the new project of Cha'an smart substation,according to the current situation of construction and design of secondary system of Smart Substation in China,the secondary design research is carried out.Firstly,this paper studies the current state-of-the-art electronic transformer,and makes a brief analysis of its working principle and characteristics.However,the reliability and long-term operation stability of electronic transformers are still lack of practical verification.Therefore,I should still choose conventional transformers in this project's turnout saddle intelligent substation.By comparing with the conventional substation and optimizing the configuration of the merging unit,the conventional transformer can be perfected by digitally configuring the local sampling.By studying and comparing several network topologies and networking modes of process layer,the optimal mode is selected.By comparison,star redundancy structure is adopted in the process layer network of Cha'an intelligent substation design,and the common network transmission mode of SV and GOOSE message is selected.Based on the requirements of intelligent substation for relay protection sampling and tripping modes,the advantages and disadvantages of direct mining,direct tripping,network mining and network tripping are compared and analyzed.Finally,it is decided that direct sampling direct tripping is adopted for relay protection in bifurcated saddle intelligent substation.The pattern.According to the general situation of Cha'an 66 kV substation project,the secondary selection of substation and the scheme design of intelligent substation are carried out,and the configuration of relay protection,monitoring system,electric energy metering system and intelligent main system are designed.Finally,by comparing the design differences between the secondary part of intelligent substation and conventional substation,a simplified secondary circuit wiring scheme of intelligent variable secondary control cabinet is proposed,and the design of intelligent variable secondary virtual circuit is realized through virtual segment.Through analysis and summary,this paper concludes the most suitable type of intelligent transformer for the development of our country at this stage and the implementation of digital in-situ sampling scheme,combined with the actual situation of bifurcation saddle transformer secondary system design,networking mode.Through the concrete demonstration,the simple and clear design method of secondary circuit and secondary virtual circuit is obtained.It provides reference and reference for the design and construction of secondary system of intelligent transformer in Dalian in the future.