A new technique to control reactive power oscillations using STATCOM

This paper proposes a new technique to control reactive power oscillations using a multipulse STATCOM. It is shown that the voltage oscillations can be controlled in a simple way maintaining the STATCOM DC voltage constant. As the reactive power flow in a specific circuit is directly related to the magnitude difference of the terminal voltages, the desired reactive power generation to control the voltage is obtained automatically when the converter voltage is maintained constant. A simplified analytical analysis was performed in a power system with an arc furnace and a 12-pulse STATCOM. The study has shown that the STATCOM can compensate the furnace reactive current, even when fast oscillations occur. The system studied was implemented in a detailed EMTP simulation program. The results show that the flicker level can be reduced at the cost of a larger size STATCOM DC side capacitor.