Adequacy assessment of time-delayed reclosing scheme for transmission system

In transmission system, the reclosing method is quite effective to restore the system after removing line faults by tripping circuit breakers. This is because the most of faults on overhead transmission system are transient in nature. Especially, high-speed reclosing scheme has a benefit increasing the continuity of supply due to fast restoration of system. It is possible to increase the transient stability due to high-speed reclosing, whereas it damages generator shafts due to fast closing. As one of alternatives, time-delayed reclosing can be proposed for transmission system. Time-delayed reclosing is a method having longer dead time than that of high-speed reclosing. However, if the system separation happens with high angle during long time, time-delayed reclosing may result in aggravation of stability. Thus, transient stability assessment must be considered for application of time-delayed reclosing. This paper models a 154kV and 345kV transmission systems using ElectroMagnetic Transient Program-Restructured Version (EMTP-RV) and performs transient stability assessment using Integral Square Error (ISE) developed by Dynamic Link Library (DLL) to assess the adequacy of time-delayed reclosing for modelled transmission system.