TCSC Controller Design Considering Torsional Vibration

Abstract

TCSC (Thyristor Controlled Series Capacitor) is used mainly to change power system characteristics to improve stability. However, it is basically a static control. Considering its quick response property, it is clear that TCSC has further potential to improve transient stability. By utilizing this remarkable advantage, in this paper, a new torsional vibration suppression control of turbine-generator system is proposed. Based on the 2-inertia system model, the controlled impedance of TCSC can directly affect the generator's mechanical behavior as a controlled input, but it's effect has nonlinearity. In the controller design, two approaches are proposed and compared. One is based on linear approximation and the other considers nonlinearity. The proposed method can be applied to various control systems using TCSC as a high performance control device.