Application Case Study Peak load in Jeju Island is 759MW and it supported by 2 LCC HVDCs, Synchronize generation & Wind Generation. 2 x ��50MVAr STATCOMs contribute to the stable operation of HVDCs & system. For the simulation, the Jeju Island power system was modeled by the PSCAD/EMTDC. PSCAD/EMTDC model having - 7 Synch. Gens with Exc. & Gov. - 2 Equivalent Wind Gens - 2 LCC HVDC link with full Ctrl. System - 2 STATCOM having with full Ctrl. System Effects of STATCOMs on power system in Jeju Island In the simulation, three(3) kind of cases are carried out by using PSCAD/EMTDC program. a) Active power / b) Reactive power / c) Grid voltage Case 1 : Two STATCOMs Case 2 : One STATCOM is Case 3 : Two STATCOMs are are in normal operation fault fault a) b) c) By comparing the actual data and the simulation results, the reliability of the modeling of the Jeju island power system has been confirmed. The simulation results have shown that the STATCOM reduces voltage fluctuation and it regulates the voltage by controlling reactive power. Comparison Voltage Regulation Peak Voltage Transiesnt Time Case 1 2.8 % 161.6 kV 35 min Case 2 3.9 % 162.7 kV 46 min Case 3 6.9 % 165.1 kV 78 min I 14 15 STATCOM STATic Synchronous COMpensator