Analysis on Special Protection Scheme of Korea Electric Power System by Fully Utilizing STATCOM in a Generation Side

Increase in power demand has required providing infrastructure, such as huge power plants and transmission lines. However, the recent trends in power system planning and operation are being toward maximum utilization of existing electricity infrastructure with tight operating margins because of new constraints placed by economic, political, and environmental issues. This might cause serious stability problems when a severe fault or a sudden outage of critical lines occurs. Therefore, the special protection scheme (SPS) has been used by generator tripping and successive load shedding to prevent a large-scale blackout by the cascading effect. If the number of tripping generators in the SPS operation is reduced, the enormous cost of power outage can be saved. This paper analyzes the enhancement of SPS via the transient stability improvement by the static synchronous compensator (STATCOM) applied to a generation side of Korea electric power system. First, its characteristic related to the SPS is described. Then, the proper capacity of STATCOM is determined with the equal area criterion to reduce the number of tripping generators. Also, the new control method for STATCOM is proposed for its full utilization. Finally, its effectiveness is verified by the case study with the practical data of Korea electric power system.