FCL application issues in Korean electric power grid

We present the analysis on 3 current-limiting practices, a bus-bar split, installation of a current limiting reactor (CLR), and application of a fault current limiter (FCL) in the KEPCO´s 345 kV power grid. The 345 kV trunk T/Ls are suffering from the high fault currents. Circuit breaker replacements are currently being practiced in many substations. As alternative ways of fault current control, application of the three current-limiting practices has been investigated. All 3 practices limit the fault currents effectively, but they create unexpected problems when coupled with the grid. The concomitant phenomena associated with the current-limiting measures such as transient stability, critical fault clearance time, and power transfer limit have been investigated and compared. The comparison in their performances shows that an FCL is the most favorable and the bus-split the least favorable solution to control fault current. But, its feasibility needs more studies