Intelligent protection relay system for Smart Grid

The authors suggest the concepts of protection relay systems for operation within a Smart Grid and describe the results of a prototype development. This paper introduces each of the system characteristics that should be considered for protection operation within Smart Grid, and the evaluation methods that were applied under both normal and faulted conditions. The results of a field trial in the 66 kV system operated by Shikoku Electric Power CO., INC indicate that the proposed system has the capability of evaluating power system characteristics in detail on a real-time basis and contributing toward supervision, coordination check and optimisation of setting values. Moreover, it has been proven that an agent system can be applied under practical conditions. Further developments aimed at commercial operation will be considered in future.