Implementing distance line protection schemes among IEC61850-enabled substations

As digital technology has developed, relays have evolved from simple electro-mechanical devices into robust microprocessor-embedded intelligent electronic devices (IEDs). Distance protection, one of the most important and sophisticated forms of substation protection, quickly and selectively detects and clears phase faults in sub-transmission and transmission lines. The installation of a substation automation system (SAS) involves implementing control, monitoring, and protection logic by programming the IEDs and providing an appropriate communication network. IEC61850 has gradually satisfied the need for a standard communication protocol so that IEDs from different manufacturers can communicate with each other. The study reported in this paper investigated the applicability of IEC61850 for distance protection. The benefits of and requirements for establishing reliable distance protection through the SAS are discussed, and detailed information about data structures and data communication is presented.