Coordinated backup protection scheme for smart substation

Based on advanced digital processing and comprehensive automation technologies, smart substation aims at improving the security, stability and flexibility of the power network. Due to the application of electrical instrument transformer, reliable and integrated intelligent device, digitization of substation area information and IEC61850 protocol, new protection scheme of smart substation can be constructed and realized. This paper presents a coordinated backup protection (CBP) scheme based on the structure and technical characteristics of a smart substation. Firstly, the framework of CBP scheme including communication network and function configuration is introduced. The protection algorithms and functions are then discussed in detail. Finally, two application issues, cooperation of CBP and the main protection, together with the hierarchical regional protection structure are analyzed and discussed.