Abstract: Grounding fault protection is an important part of power system protections. Conventional grounding fault protection device has many problems, such as limited available information, slow response, complex algorithm and low reliability, which seriously affect the quality of power supply and operational efficiency. However, smart substation offers a new way to solve the problem of single-phase grounding protection. Based on multi-intelligent substations, a regional centralized control smart power supply system was built, the information was shared through GOOSE network, and a fault identification and isolation system was also established, which can make the information concentratedly processed and comprehensively judged. Based on the intelligent control technology for peer to peer data exchange among distributed terminals, the principle of zero sequence full current power direction was put forward, the criterion of single-phase grounding protection based on multi-criterion and the key technologies of GOOSE network transmission was addressed, which can ensure the selectivity and reliability of single-phase grounding protection, and effectively solve the traditional problems and provide a theoretical foundation for multi-criteria relay protection of smart Substation.

Key words: smart substation, grounding fault protection, GOOSE, principle of zero sequence full current power direction