Time-optimal series capacitor control for damping interarea modes in interconnected power systems

Controllable series capacitors have been proposed to damp power swings resulting from large transient disturbances in two-machine power systems. In this paper, the authors propose a time-optimal series capacitor control to damp interarea modes in multi-machine power systems. To find the switching line, they apply the slow coherency transformation to the full power system and project a slow subsystem trajectory found from the trajectory reversing method onto the predominant interarea mode. The method is illustrated by the time simulation of a six-machine power system with two interarea modes and is shown to give the desired result.