Research And Application Of Key Technologies For Smart Substation

Proposing of the concept of smart grid has opened up new space for the establishment of efficient and green energy system. Smart substation is an important part of smart grid. At present, China has accelerated the pace of building smart substation. The first pilot projects, which are designed in accordance with all requirements of the new smart substation, cover most provinces of and various voltage levels.IEC61850 standard and electronic transformers, which are key technologies for the implementation of smart substation, are further studied and researched in recent years. Application of new technologies and standards bring changes for network topology of substation automation system. The network structure of substations in projects presents complex diversity. Meanwhile, the close relationship between performance of relay device and the network structure, the problems of synchronization for samples and the veracity of action and the use of network to extend the functionality of digital protection are all required of deep study in smart substation content.This paper focuses on the key technology of smart substation. Firstly, study of the electronic transformer has been carried on .Through simulation experiment; this paper analyzes the saturation characteristics of electromagnetic transformer under different loads and the transmission characteristics and accuracy of optical transformer. This paper also analyzes operation stability, advantages and disadvantages of the three electronic transformers by running the practice in the cold region. Secondly, This paper studies the communication protocol of smart substation and analyze the main differences of standards IEC 61850 and 103 from three aspects including range of applications, communication model and information exchange. Thirdly, this paper studies the network structure of the automation system of smart substation. This paper analyze the network topology of substation, the transmission network for samples of the process layer, GOOSE nets, synchronized network. This paper also gives a brief description of the odd and even mechanism of GOOSE network. Fourthly, This paper researches on the issues related to digital protections. By analyzing the problems of synchronization for protection samples and the real-time of action, this paper not only concludes the synchronization algorithm of linear interpolation and the table tennis algorithm but also proposes measures to improve veracity characteristic of protections. By analyzing the implementation of export logic of protections, this paper has elaborated the concept of export logical matrix of digital protections. This paper also briefly analyzes the impact of grounding resistance on digital protection.Finally, this paper briefly analyzes the practical application of the 220kV substation according to the actual project and provides a reference to the design and construction of the smart substation in the future smart substation.