Mitigation of Power System Forced Oscillations: An E-STATCOM Approach

Abstract

With the integration of renewable energy resources and variable loads into power grid, power oscillations caused by persistent external fluctuating forces are becoming more prevalent. Termed as “forced oscillations (FO)”, such phenomena could happen even when the grid is with good damping characteristics. Therefore, conventional mitigation methods based on improving damping are rendered less effective. By leveraging the new control capability offered by static synchronous compensator with energy storage (E-STATCOM), a novel approach to mitigate FOs is proposed in this paper. A control strategy based on resonant controllers is adopted to modulate active and reactive power supplied by E-STATCOM. It is theoretically shown that FOs propagating from the disturbed area to other areas can be effectively eliminated by this method. Besides, we derived the analytical relationship among the location, the capacity of E-STATCOM and the suppression performance. Case studies demonstrate the effectiveness of the proposed method.

Keywords

• Forced oscillations
• mitigation
• STATCOM
• energy storage
• resonant controller
• active and reactive power control