Fast contingency screening for online transient stability monitoring and assessment of the KEPCO system

A fast contingency screening algorithm using SIME for the transient stability monitoring of the KEPCO system is implemented. This method evaluates the first-swing stability of a large number of contingencies in a short time with reliable accuracy. The salient features of the proposed screening algorithm are as follows. First, a critical cluster of generators is identified by a new index in the early stage of the time domain simulation. Thus, the computational time required for finding the equivalent one machine infinite bus system can be reduced significantly. Second, clustering critical machines can perform even in very stable cases. This allows us to avoid the extra calculation of the time trajectory that is needed in the SIME for classifying the stable cases. Third, the screening capability is improved using the power-angle trajectory and subdividing the contingency classification. The test results on the KEPCO system show that the proposed method can be adopted as a contingency screening function and the transient stability assessment for the transient stability monitoring of the KEPCO system.