VSC based series FACTS controllers for damping local mode oscillations

In the last decade, various nonlinear control techniques have been applied in FACTS controller design. The performance of nonlinear controllers is influenced by the parameter uncertainty and external disturbance. This paper mainly discusses a novel approach of robust variable structure control (VSC) based series FACTS controller design for damping local mode power system oscillations. The VSC-based controllers for series FACTS devices , including thyristor-controlled series capacitor (TCSC), thyristor-controlled phase shifting transformer (TCPST) and unified power flow controller (UPFC), are presented. The designed controllers can provide significant damping to the local mode oscillation. Robust performance of the proposed controller in the SMIB power system is evaluated by computer simulation.