The International Electrotechnical Commission (IEC) 61850 protocol, an international standard for substation automation system communication protocols, is being used globally, and the new substations that was completed from 2013 through pilot projects and R&D are being built in Korea from 2007 as digital substations using IEC 61850 protocol.
The number of newly built digital substations is less than 10 percent, and the existing substations account for most.
There is a disadvantage of replacing existing substations with digital substations because they require replacing all major power facilities, which is costly and a long construction period.
Therefore, research on systems that can be used with operating on-site facilities in existing substations and the substation Automation (SA) facilities used in digital substation automation systems has recently become necessary.
In this paper, field information processing devices have been designed and validated through empirical tests to replace existing substation power facilities, remote terminal units (RTUs) with various signals for transformers, GIS (Gas Insulated Switchgear), and related facilities on the IEC 61850 basis applicable to digital substations.
A digital substation automation system was designed by applying IEC 61850-based field information processing unit, Ethernet switchboard, SA system board and operating system that can communicate IEC 61850 with existing RTU-based systems.
Based on the design, a higher operating system program which is IEC 61850 client, and a communication analysis program could be used to verify that standard time synchronization, monitoring, control, GOOSE for interlock and logic, and site control contacts operate in accordance with IEC 61850 communication specifications and are suitable communication services.
In addition, by replacing the existing RTU and switchboard type substation automation systems with digital substation automation systems applied with IEC 61850, it was confirmed that substations could be applied as digital substation automation systems without replacing power facilities such as breakers and transformers in existing substations.